SOME EFFECTS OF ENVIRONMENT AND HABIT ONCAPTIVE LIONS.
By N. HOLLISTER,Superintendent, National Zoological Park, Washington.
INTRODUCTION.The series of over 100 East African lions now in the collectionof the United States National Museum was recently spread out forstudy. Marked diiferences between wild-killed specimens and thosewhich had died in the National Zoological Park in Washington wereat once apparent. These differences involved both the skins andskulls, and from the fact that five of the park lions were of knownhistory and were from a locality abundantly represented by wild-killed specimens, the uniform differences between the two lots, wildand park-reared, seemed more significant than would otherwise havebeen the case.The 11 Zoological Park lions preserved in the collection agreeamong themselves in all essential details and differ uniformly fromwild-killed lions. In the following remarks, however, the notes pre-sented, unless otherwise stated, refer to the restricted subspeciesFelis leo massaica,^ represented in the collection by 59 specimens,54 wild-killed and 5 park-reared. The five park-reared animalshave definite and complete records. They were captured nearNairobi, British East Africa, and comparisons of skins and skullsare made with specimens of equal age, killed in the same vicinity.All chance of error from the use of park animals of unknown origin,which might be crosses of different subspecies bred in captivityor specimens of wild forms not represented in the Museum collection,is thus eliminated.
? In 1910. when reporting on the mammals collected In British East Africa by JohnJay White (Smithsonian Misc. Coll., vol. 56, No. 2, p. 11), I referred the Nairobilion to Fclis Ico xahakietiais Lonnberg, described from Kilimanjaro. After working overthe much more abundant material since received at the Museum I am unable to recognizethis race, and now refer those lions to the earlier-named Felis leo massaica Neumann,described from Kibaya, German East Africa.Proceedings U. S. National Museum. Vol. 63?2196.77403?Proc. N. M vo) . .53?17 ^1
2
177
178 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.53.The wild-killed material was collected chiefly by Dr. W. L. Abbott,John Jay White, Col. Theodore Roosevelt, Kermit Roosevelt, PaulJ. Rainey, and Edmund Heller.The histories of the five Zoological Park specimens of Feiis leomassaica have been given me by Mr. A. B. Baker, assistant super-intendent of the National Zoological Park. It seems important togive his account in complete detail.The history of the five lions from East Africa, .so far as we know it, is asfollows
:
In May, 1909, while the Smithsonian expedition was at Nairobi, Mr. W. N.McMillan offered the lions and several other animals to the National Zoo-logical Park, through Dr. E. A. Mearns, who reported the offer here by letter.He was authorized by cable to accept the animals on behalf of the park.I first saw the lions September 19, 1909. They were then at Mr. McMillan's
?' Juja Farm," some 23 miles northeast from Nairobi. There were two males,said to be then about 20 months old, and three females, one of which was saidto be about 19 months old and the other two about 27 months. All were saidto be fioni the region about the Nairobi, but I was able to get the exactlocality of only one?a male which was captured by Mr. G. L. Langridge inthe Mua Hills, out some 25 miles from Machakos station. When captured itwas a little larger than a house cat. I was told that all of the others werecaught while small cubs. The lions were put into shipping boxes October 15and 16, left .luja Farm on a big freighting wagon at noon October 18, and ar-rived at Nairobi late on the 19th. The boxes were put under a shed in therailroad freight yard there until the morning of October 26, when they wereshipped by rail, and should have reached Mombasa early in the morning ofthe 27th, but did not arrive there until noon of the 28th, because of thederailing of the train, which made it necessary to transfer all the boxes toother cars. They were transferred to the steamship Melbourne shortly afternoon on the 2Sth and arrived at Port Said at 8 p. m. November 8. Theywere kept on a lighter in the harbor there until November 21, when they weretransferred to the " tramp " steamer MoltkefeU sailing that day. The shipspent the night of November 25-26 at Malta, and arrived at PhiladelphiaDecember 17. The lions were forwarded from Philadelphia December IS,reached Washington early on the 19th, and were transferred to cages in thelion house at the park about noon of that day.At Juja Farm the five lions were kept together in a stone building, perhaps25 feet long, 15 feet from front to back, and 8 feet high. This was divided bya partition running from front to back, into two compartments, perhaps 15and 10 feet wide. The roof was of galvanized iron. The floor was of con-crete, with good drainage so that it could be washed out with a hose. All sideswere tight, except the front, which was closed with an iron grating. Theplace was poorly lighted and the animals had little chance to get into the directsunlight. There were low wooden shelves in the corners, which the animalsseemed to occupy most of the time when not walking. The three younger lionswere good tempered, but the two older females were quite savage, probablyfrom having been teased. The shipping crates were about 3 feet wide, 5 feetlong from front to back, and 3 feet 6 inches high, Inside measurements. Therewas a steel grating in the front, with stout wire netting over it, so that a pawcould not be put out. A space was left at the bottom wide enough to admitfood and pan for water. This space was closed except when food or waterwas given. There was a ventilating opening, about 8 inches square, in the
NO. 2190. EFFECTS OF ENVIRONMENT ON LIONS?HOLUSTER. 179
rear end of the box fitted with a grating. This opening was covered over whenthe animals were shipped from Port Said to protect them from the colderweather that would come during the remainder of the journey. At the parkthe lions were put into cages 10 feet wide, 8 feet deep from front to back, and7 feet high. They were kept in these for about two years and then transferredto cages 12 feet 6 inches wide, 12 feet deep from front to back, and 9 feet high.These latter cages connect with outdoor cages 20 feet wide, 33 feet deep fromfront to back, and 10 feet high. The lions had free access to these outsidecages during the day, whenever the weather was suitable.While they were at Juja Farm the lions were fed mainly on zebra and kon-goni (Coke's hartebeest), which usually were to be had for the shooting withina mile of the house. The whole dressed carcass was used and the lions weregiven sections from any part of it. They were liberally fed and apparentlyhad a fair proportion of bone with the meat. I gave them zebra meat tillOctober 20, then beef, mostly neck and shoulder, till November 1. Owing toan accident on the railroad it was impossible to give them either food or waterfrom 6 a. m. of October 2G to noon of October 28, although during the first daythey were exposed to the hot sun on an open car. From November 3 to 7, threesheep, bought at Djibouti, were fed them. November 9 to 22 they had beef,and the 23d and 24th a goat each day. From November 2G to 30 beef fromMalta v^as fed. This was hind quarter, largely " round," as I found that beeffrom any part of the body was priced the same, and hind quarter gave the mostmeat for the money. From December 1 to 16 the lions were fed on goat meat,one goat being butchered each day, or one every second day, as the supplydwindled. From December 17 they were fed on beef. At the park the lionswere given cuts of beef from brisket, shoulder blade, and short ribs, with, occa-sionally, upper shin or shoulder cut. At first they were given 8 pounds daily,which was increased, as they grew, to 10, 12, and finally a maximum of 14pounds during the winter months to the two males. Most of this was cold-storage beef, and occasionally it was necessary to use some that had been frozen.All of the lions appeared to be in perfect health when shipped and when theyreached the park, except that the male (No. 2297) had a smnll abscess in onecheek, and that all were infested with roundworm and tapeworm. The tape-worm was probably acquired from the kongoni, the meat of which I was told isgenerally " measly."The male lion No. 2297 (U.S.N.M., No. 197944) died March 1, 1914, ofchronic gastroenteritis. He had been ill for about 10 months, could not prop-erly digest his food, and was emaciated. He became blind about 18 monthsafter his arrival at the park and remained so for about three mouths, thenbegan to recover liis sight, the pupil, which had been fully expanded, gradu-ally contracting as the eye responded to the light.*Male No. 2367 (U.S.N.^M., No. 199707) was shot .July 1, 1915, as he was unfitfor exhibition. Autopsy showed considerable softening at the base of the brain,but other organs appeared to be practically normal. This lion became blindabout 15 months after arrival and did not regain sight. The effects of thebrain iesion were first noticed about two years before death and increased untilthe animal was finally killed. He always ate well and was in good flesh.Female No. 2209 (U.S.N.M., No. 176201) di'ed March 22, 1913, from choking.She was a hasty eater, bolting her food, and this time a large piece of meatlodged in her throat and she died before help could be given. She kept in
1 This Is the only skull among the five which shows p.ithologlcal conditions In thebone. The shape and general characters of the skull are exactly as in the others, butthe bone is very light and flaky.?N. H.
180 I'ROCEEDINGS OF THE NATIONAL MUSEUM. vol.05
excellent flesh, although fed only 10 pounds of beef, but sometimes, after boltingher own iwrtion, she would rob another lioness of part of its food. She washeavily infested with ascaris worms. She was the youngest of the three lion-esses. She was bred several times, but never became pregnant.Female No. 2276 (U,S.N.M., No. 197137) was shot December 25, 1913, as shewas unfit for exhibition. In November, 1912, she was removed to a hospitalcage on account of her difficulty in walking. She ate well and remained inexcellent flesh, but the trouble continued to increase until she was killed. Theautopsy did not show any serious lesions. She was given but 10 pounds ofbeef per day. She came in heat several times, but would not allow the male toapproach her.Female No. 2360 (U.S.N.M., No. 199524) died of pericarditis February 14, 1915,about six weeks after the first symptoms of illness were noticed. She was thelargest of the lionesses, and her daily ration was 11 pounds of beef. She wasbred several times, but did not become pregnant.Not knowing just what data you might want, I have given the history withmuch detail.The conspicuous external characteristics which distinguish theseMcMillan lions (as the five park-reared specimens will hereafter becalled) from wdld-killed animals of the same age and from the sameregion are much darker color, more luxuriant mane, and much longerhair tufts on back of elbows. The skulls are very different in gen-eral proportions. Those of the McMillan lions are much shorterand broader than in wild animals; their zygomatic arches are morewide-spreading, and the bones of the arches are much thicker andmore cylindrical. (See pis. 22-25.) These skulls have further-more a greater rostral and mastoid breadth nnd numerous minordistinguishing characters. Only one of the McMillan skulls showsevidence through pathological changes of the life in captivity, andthis condition has affected the quality of the bone and not the shape,as the skull agrees in all the relative dimensions with those of otherpark lions in perfect condition.COMPARISON OF McMILLAN LIONS WITH WILD-KILLED SPECIMENSFROM VICINITY OF NAIROBI.COLOfi AND ESTEKNAI, ChARACTEKISTICS.At the time of their arrival in Washington the McMillan lionswere the subject of remark on account of their exceedingly palecoloration. Most of us had been accustomed to the much darkerpark lions, usually seen in captivity, and these new arrivals seemedparticularly beautiful animals because of the strange pale grayishbuff coloration, which was, as a matter of fact, the normal colorationof the subspecies to which they belonged. Wlien, after the deathof the animals, the skins reached the museum, the great darkeningof the general color since their arrival was at once noted. Thedegree of color change is in direct relation to the period of life inWashington. In the following notes on color the skins have been
NO. 2106. EFFECTS OF ENVIRONMENT ON LIONS?HOLLISTER. 181observed from in front ; they present a somewhat darker aspect whenviewed from the rear.Males.?Wild-killed adult males of Felis leo massaica are all ofa very uniform color. The general appearance is that of grayishbuff animal, a very light-colored lion with virtually no deep ochra-ceous or dark brown in the hue of the skin. The general body coloris the effect of pinkish buff hairs tipped with blackish, the dark tipsconsiderably grizzling the otherwise general pure buff coloration.The hairs of the belly, throat, and insides of limbs lack the blacktips and these parts are, as a consequence, almost pure pinkish buffin color. The tufts at the back of the elbows are comparativelyshort, mixed buff and brown. The mane varies greatly in differentanimals, but averages much shorter than in captive lions, is rathercoarse haired, and comparatively light in color. It is produced onthe withers in a narrow line and is almost entirely wanting on theshoulders. The tail is more gray, less buff than the body, but lacksany suggestion of ochraceous.The first male McMillan lion to die in the park was No. 197944,March 1, 1914. He had been in "Washington a little over four yearsand was, according to Mr. Baker's records, about six years of age atthe time of death. The skull shows a fully adult animal with basi-sphenoid suture obliterated and with a fully developed sagittal crest.The skin is considerably darker, more ochraceous buff or cinnamonbuff, than in wild-killed males of the same age. The general colorof the back is more cinnamon buff; the black hair tips, thoughpresent, are less conspicuous against the darker ground color and thegeneral appearance is therefore less grizzled, more reddish. Thebelly, throat, and inner sides of limbs are decidedly pinkish cinnamoninstead of pinkish buff, as in all wild-killed males. The tufts at theback of elbows are long, luxuriant, and silky, mixed deep black andbuff?much longer and fuller than in any wild-killed animal. Thereis a supplemental tuft of dark brown hair on each side of the lowerbelly. The mane is longer, more sillcy, and more cinnamon buff incolor than in wild-killed lions. It extends far back on the withersand laterally onto the foreparts of the shoulders in curly masses.The tail is decidedly more ochraceous and black, instead of buff andblackish as normal in the subspecies.The second male McMillan lion (No. 199707) died in the ZooJuly 1, 1915, at an age of about seven and one-half years, five andone-half years of which had been spent in Washington. The skin ofthis lion is decidedly darker than any other East African specimen.The appearance of the animal has been greatly changed?from a palegrayish buff to a dark brownish ochraceous. The general color of theupper parts and sides of the body is dark tawny olive; of the belly^throat, and insides of limbs cinnamon to pale ochraceous tawny. Thft^
182 PROCEEDINGS OF THE NATIONAL MUSEUM. vor-. 53.tufts at backs of elbows are extraordinarily long, thick, and silky ofrich black and buff hairs. Whereas in wild lions of equal age thehairs of these tufts average about 60 millimeters in length and arerarely over 80, in this specimen they are 200 millimeters in length.The mane is remarkably full and is not approached in this respectnor in its deep coloration by those of wild-killed lions. It is full andwide on the withers and luxuriant on the lower neck and anteriorshoulders. The whole head, face, and mane are richly tinged withdeep tawny and ochraceous. The tail is rich and dark in color, theblack tip offering little contrast in shade from the general color ofits upper side.Females.?The wild lioness of Felis leo massaica averages some-what darker in color than the male, but the coloration in its essentialelements is the same?a grayish buff general color, the effect of apale pinkish buff ground color mixed with the blackish of the hairtips. Except in very rare cases there is little or no indication ofreal tawny or ochraceous in the general coloration.The first of the three McMillan lionesses to die was No. 176201,March 22, 1913. The skin is much darker than the average wild-killed massaica and is very much darker than when the animalreached the Washington Zoo in 1909.The second female (No. 197137) died December 25, 1913. Theskin of this lioness is somewhat darker than the wild animal and isconspicuously cinnamon colored, not at all the grayish buff of a nor-mal massaica. The hoWj is pure cinnamon color, not buff as in allthe wild lionesses of this form. The coat is long and full.The last female of the McMillan lions died February 14, 1915,after over five years in the Washington Zoo. The skin is very darkand has been greatly changed since its arrival. It is very muchdarker than any skin of a wild-killed female massaica in a largeseries, and at a short distance looks like a tawny blackish animal.It represents the extreme of change in color in the lioness as No.199707 does in the lion. The back is dark brownish tawny olive, richand glossy.From the above facts it is evident that life in Washington con-siderably darkened the color of these McMillan lions. Young wildlions are much darker and richer colored than adults, quite the re-verse of the condition in the McMillan lions. From Mr. Baker'snotes it is seen that while the captive lions were kept during theirstay in Africa in a virtually sunless and rather dark den, in Wash-ington they had abundant access to out-of-doors yards. In view ofthe success of Mr. Beebe's experiments in increasing the pigmenta-tion in birds by confinement in superhumid atmosphere,^ it would
1 Zoologica, vol. 1, No. 1. New York, 1907.
NO. 2196. EFFECTS OF ENVfliOXMUNT ON LIONS?UOLLIHTER. 183perhaps seem unnecessary to go beyond the theory that the humidclimate of Washington has acted in a similar manner on these lionsfrom the highlands of East Africa. The effect has been to changethe color of living examples of Felis leo massaica to a darker colorvery much resembling that of Felis leo nyanzm^ the lion of the morehumid Victoria Nyanza region.While the data available do not show very great difference in meanrelative humidity between the weather station at Machakos, BritishEast Africa (near where the lions were captured), and Washing-ton, District of Columbia, the average monthly precipitation atWashington for a term of years is considerably greater. At En-tebbe, Uganda (near the type-localit}'- of Felis leo nyatizai)^ bothmean relative humidity and monthly precipitation are higher thanin Washington or in the British East African range of Fells leomassaica. The problem is so complex and there are so many possi-ble factors which are little understood, that it seems unwise to hazarda positive opinion on the cause of the great color change in theMcMillan lions. Alterations in the quality of light to which theanimals were exposed, as well as the changes in the conditions ofmetabolism due to a life in captivity under abnormal treatment anddiet, are factors that must be considered.Mr. F. C. Selous,^ after writing of the variability of the mane inlions apparently adult, says:Quite recently there was a fine lion in tlie Zoological Society's Gardens atRegent's Park which was presented by Messrs. Grogan and Sharpe. Thisanimal was caught near the Pungwe River, in southeast Africa, and broughtto England by these gentlemen when quite a small cub. When full grownit developed a very much finer mane than I believe has ever been seen in a wildlion that has come to maturity in the part of Africa from which it wasbrought. Similarly, some 30 years ago there was a very fine lion in the So-ciety's Gardens which was brought by Colonel Knox from the Soudan. ColonelKnox took me to the Gardens to see this animal, and pointed out to me thefact that it had developed a far finer mane (extending much farther back overthe shoulders and under the belly) than any man had ever seen in a wild lionin the country from which it came. Lion cubs brought to this country fromIndia also grow fine manes, though I do not think that there is any record of alion ever having been shot in India with anything more than a fairly goodmane. The fact that lion cubs captured in any part of Africa or Asia, andbrought up in the comparatively cool and damp climate of western Europe,always?or nearly always?grow fine manes, which usually cover the wholeshoulders and often extend all over the undersurface of the body, and thefurther fact that in the hotter parts of Africa lions always have very scantymanes, but on the high, cold plateaus often develop good, and occasionally veryluxuriant manes, appears to me to show that a heavily maned lion is a reversionto an ancient ancestral type, first evolved in Pleistocene times In a coid andinclement climate.
? African Nature Notes and Reminiscences, pp. 83, 84. 190S.
184 PROCEEDINGS OF THE NATIONAL MUSEUM. tol. 63.Mr. Selous has noted that while the eyes of wild lions are of a
" flaming yellow " in color, those of animals reared in captivity areoften brownish. Skull Chabactebistics.The greatest interest in the study of the McMillan lions comparedwith wild examples from the same region lies in the skull. Theskulls of the captive animals are of a definite, uniform shape anddiffer from all the skulls of wild-killed lions in the Museum col-lection in a number of conspicuous characters. They are broaderand shorter, more massive and bulky, and exhibit abundant relativedifferences which would be instantly accepted as of " specific " valuein wild animals. The obvious reason ;for these great differences isthat the principal muscles operating the jaws and neck (thosemuscles used by a wild lion in mauling and killing game, biting,gripping, and shaking) have had little influence on the shape of thebones during development. In a wild-reared lion these powerfulmuscles naturally and in a normal way mold the growing skull, par-ticularly in the regions of their attachment.The most conspicuous peculiarities of the McMillan lion slcuUsare the greater (relative and actual) zygomatic breadth, the largerostra, and the great distance across the base of the skull at the mas-toids. While actually measuring less in condvlobasal or greatestlength than many of the wild massaica skulls of equal age, theyhave a far greater zygomatic breadth than any, averaging about 30millimeters more in males and 20 millimeters more in females. (Seedetailed measurements, p. 192; and pi. 24.)All five of the McMillan lions, male and female, are, as already noted,fully adult, the skulls with basal sutures obliterated. All agree inmost particulars in the differentiating characteristics, and compari-sons may be made with wild-killed skulls of Felis leo massaica fromthe same vicinity and of equal age, without special designation ofspecimens by number. The differences are sometimes most pro-nounced in males.Regions of attachment of the massete?' muscle.?Contrary to theusual textbook definition of its function, the masseter muscle un-questionably furnishes the chief gripping power; it is the one mostexercised during use of the canine and incisor teeth.'^ Aided by the
' In this connection see Keith, The Antiquity of Man, 1915, pp. 4C2-4G3. The lion,like all cats, is a biting animal of the highest type. While there is intimate relationshipbetween the functions of the masseter and temporal muscles, and the two masses areactually connected, each nevertheless is the prime power in the definite mechanical actionof separate parts of the dental row. The masseter, as stated above, has primarily todo with the front teeth (the canines and incisors), while the temporal is chiefly con-cerned with the niolar-premolar row, and the process of cutting and chewing ratherthan biting and gripping.
NO. 2196. EFFECTS OP ENVIRONMENT ON LIONS?HOLUSTER. 185temporal and internal pterygoid muscles, it locks the jaw and makesthe grip firm. The region of its origin in the McMillan skulls isgreatly changed from the wild type. The malar ;ind the zygomaticprocess of the temporal bone ^ have been almost uninfluenced by themuscle and have to a certain degree retained distinctive charactersof juvenility. In wild lions this muscle has exercised very greatinfluence on the bones of the zygomatic arch. The following char-acters, which appear to be largelydue to the nonaction of thismuscle, separate easily the Mc-Millan lion skulls of either sexfrom wild skulls of equal age:Zygoma more spreading ante-riorly; malar very thick andwide; squamosal arm subtereteand heavy, almost rounded incross section and not at all con-cave on inner surface, with nosuperior margin for strong mus-cle attachment [in skulls of wild-killed specimens the squamosalarm of the zj'goma is thin andlight, but strong; it is greatlyhollowed out on inner surfaceand has a sharp superior margin]. The region of insertion, theouter lateral face of the ascending mandibular ramus, is also greatlymodified. In the McMillan skulls it is comparatively heavy andthick, but is smooth and poorly fitted for muscle attachment. Themargin is smooth and rounded. The great zygomatic breadth of theskull of the captive lion is partly due to the rounded squamosal arm.Some measurements of two old adult male skulls of equal age areas follows
:
1 2Fios. 1-2.?Cross sections of ztgomata of wild-killed AND PARK-REARED LION SKULLS, MADEat inferior point of zygomatico- temporalsuture.?(1) wild-killed (no. 155443, nairobi,British East Africa); (2) park-reaeed (No.199707, "McMillan lion.") ADin,T males ofEQUAL AGE. NAT. SIZE.
Condylobasal lengthZygomatic breadthGreatest thirknes." of zygoma at middleActual thickness of bone at middle of zygomaThickness at inferior zygomatico-tomporal sutureIleight of arch at middle, across malar and zygomatic process oftemporal 31.9
\\\\A lion
186 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.53.Regions of attachment of the temporal muscle.?The temporalmuscles, chiefly concerned with the cheek teeth rather than with thefront teeth,^ have had less influence in changing the type of skull ofthe captive lion, than have the masseters. The lion in captivity has,as a matter of fact, used his temporal muscles in much the normalway of a wild lion, whereas the natural function of the masseter isalmost entirely discontinued in a captive animal which does not killits own prey. As a precaution against the natural tendency of theanimals to bolt their food without mastication, the lions in theZoological Park are regularly fed pieces of meat with large bones.The region of origin, the entire side of the skull posteriorly, issomewhat modified. The brain case has been less subjected to pressureby these powerful muscles than in the wild lion; the muscles have hadless to do W'ith moulding its shape during the process of absorptionand ossification ; and it, as a consequence, is less compressed laterally.Wild lion skulls of equal age have smaller braincases, more sharplymarked sagittal and lambdoidal crests. The region of insertion, theinner surface of the ascending ramus, is slightly smoother in theMcMillan lions, but is little modified.Capacity of the hrahicase.?As stated above, external measure-ments of the braincase in wild lions are less than in park-rearedanimals of equal age. The capacity of the braincase, however, isconsiderably greater. Young adults of each, as usual among carni-vores, have greater braincase capacity than old or aged adults. Thebones forming the cranium of the Zoo lion are thicker, and theactual size of the brain is less than in w^ild-killed examples. In thecase of the McMillan lions the capacity is about 50 cubic centimetersless in males and about 40 less in females, than in wild-killed ex-amples of equal age from the same locality.The "Richardson lion," from the New York Zoological Park, cele-brated as the record skull for greatest breadth,^ and the Menelik lion,the type-specimen of Felis leo roosevelti, are both park-reared ani-mals of uncertain history but they show the skull characters of cap-tive lions to a marked degree. Even the skulls of these enormouslions, although the animals represent forms unquestionably larger ina wild state than Felis leo nmssaica, have less braincase capacity thanany wild-killed examples of the East African lion.
1 A fox skull, in the Vienna Museum, with a defective left lower carnassial tooth,exhibits an asymmetrical condition because the animal used its right temporal muscleto such a degree as to develop this muscle far above the nornial strength, while theleft temporal muscle was very weak from little use. The right temporal ridge on theskull was pushed up almost to the sagittal line while the left temporal ridge remainedbelow its normal elevation for that age. The occipital crest is likewise asymmetrical.(Toldt, Zool. Anz., vol. 39, pp. 17G-191, figs. 1-4. July 4, 1905.)2 See Koosevelt and Heller, Life-Histories of African Game Animals, vol. 1, 1914,p. 225.
NO. 2190. EFFECTS OF ENVIRONMENT ON LIONS?HOLLISTEB. 187Following are some measurements of the capacity of the brain-case in fully adult lions: MALES.
PROCEEDINGS OF THE NATIONAL MUSEUM. vou 63.
muscles, naturally less developed in the animal reared in captivity.The digastric muscle, of quite another function, but powerfullydeveloped in the cat, and having its origin on the paroccipital processand inward, bordering the posterior margin of the auditory bullae,is no doubt somewhat responsible for the development of shape inthis part of the skull as well. After a preliminary movement of th"hyoid muscles, it is the chief agent for depressing the jaw. Thecephalo-humeral and other muscles and the ligamentum nuchae attachto the base of the skull but, in this problem, are of little importance.The mastoid breadth in a wild-killed adult male lion from Nairobi(No. 155443) is 135 millimeters; in a McMillan lion of the same age(No. 199707) it is 152.The lambdoidal ridge and occipital bones are broader in the Mc-Millan skulls than in any skulls of wild lions. Here again thesplenius and complexus muscles, through nondevelopment, havefailed to influence the bone as in a normal wild lion w^hose life isone of tearing and shaking of strong prey.The development of powerful neck muscles evidently begins in thewild lion at an early age. Roosevelt and Heller write of the yomiglion : ^Wlien the cubs are three months or so old, they habitually travel with themother; then, instead of eating her fill at a kill and afterward returning tothe cubs, the latter run up to the kill and feed at it with their mother. Wefound flesh and hair in the stomachs of two cubs; for they begin to eat fleshlong before they stop suckling. While still very young they try, in clumsyfashion, to kill birds and small animals. By the time they are four or fivemonths old they sometimes endeavor to assist the mother when she has pulleddown some game which is not formidable, but has not killed it outright beforethey come up; and soon afterward they begin to try regularly to help her inkilling, and they speedily begin to help her in hunting and to attempt to huntfor themselves. Evidently in their first attempts they claw and bite their preyeverywhere; for we found carcasses of zebra and hartebeest thus killed byfamily parties which were scarred all over.Remarks on Other Park-Reared Caknr'ores.Park lions in the museum collection recorded as from Abyssinia,Sudan, and Somaliland, and others without definite history, agreein all essential details with the McMillan animals. The Meneliklion, which has been made the type-specimen of a new^ subspecies,'is virtually inseparable by any character, so far as the skull is con-cerned, from the McMillan lions. The differentiating characters asgiven in the description are exactly those separating park-rearedfrom wild-killed specimens of the East African massaica; the speci-men was compared with wild examples. This animal was presented
1 Life-Histories of African Game Animals, vol. 1, 1014, pp. 105, IGG.2Fe?is Ico roosevclU Heller, Smithsonian Misc. Coll., vol. 61, No. 19, p. 2. November8, 1913.
NO. 2100. EFFECTS OF ENVIRONMENT ON LIONS?HOLLISTER. 189to President Roosevelt by Emperor Menelik of Abyssinia and diedin the Washington Zoo. All the characters of skin and skull pointto a life-long captivity. The skin shows a long, full mane whichconnects from the neck with the elbow tuft. The colors are almostexactly as in the McMillan male longest in captivity, except that themane is slightly darker and is curly instead of straight haired.Black manes and curly manes are individual variations found inmales of equal age from one locality. One male massaica collectedby Dr. W. L. Abbott has a much blacker mane than the Meneliklion.An old male lion from Sir Francis Reginald Wingate, Omdurman,Sudan, which died in the Washington Zoo, is of the same type andshows all the characteristic evidence of a long life in captivity. Themane extends in a curly mass from the withers on to the shoulders,but does not connect between the neck and elbow tuft; it is largelyblack. This skin exhibits small tufts of hair on each side of thelower belly, like the McMillan male number 197944.In a large series of leopard skulls in the collection a single speci-men is from a park-reared animal. It can instantly be selected fromthe series by a blindfolded person familiar with the characteristicshape of the bone in the zygomatic arch of the McMillan lions.Wolves born and reared in the Washington Zoo from parents ofknown history show the same characteristic shapes of these boneswhen compared with wild-killed animals of the same subspecies.The differences are much less in the wolf, however, than in the greatcats.No changes in the teeth have been noted in the park-reared animalsof any species, although the teeth of the McMillan lions do actuallyaverage slightly less in size than in wild-killed animals. The varia-tion, shown in the following table, is so slight as to be of little con-sequence without further data:Dental measurements of adult Felis leo massaica.
Locality.
Wild-killed males.Kapiti StationDoXJlu StationUlukenia HillsNairobiLaikipia PlateauMcMillan mxdes.
Number.
190 PROCEEDINGS OF THE NATIONAL MUSEUM. VOL. 53.Dental measurements of adult Felis leo massaica?Continued.
Locality. Number. Alveolarlength cfupper Uppercamassial. Second upperpremolar. Lower molar.
Wild-killed females.Dlu StationDoDoKapiti StationDoDoDo ,DoWamiHillKitangaMcMillan females.
182308182309182311182293182324182326182421182423161914182315
197137199524
mm,.23.624.920.721.920.919.421.921.221.723.2
19.119.2
mm.35.4X17.738.5X19.433.6 X 15.935.2X17.133.9X16.833.2X15.532.5 X 16.333.1X17.033.4X15.635.6X16.533.6X15.232.5X15.4
mm.23.8X11.727.7X14.122.3X11.523.7X12.923.6X11.722.1X11.223.1X12.221.8X12.5
i 21.7X11.122.2 X 12.022.9X10.521.7X11.3
mm.25.1X12.728.4X14.624.6X13.225.3X13.925.3X12.423.9X12.123.3X12.724.6X13.624.2X12.125.6X13.223.8X11.922.9 X 12.4SUMMARY.Specimens of the exceedingly pale Felis leo massaica brought fromthe British East African highlands to Washington change from thenormal pale grayish buff color of the race to a darker color, re-sembling that of Felis leo nyanzce of the Victoria Nyanza re-gion. The color deepens with each successive moult for five yearsat least. The cause of this color change is unknown, though humidityis probably a factor of some importance.The skulls of lions and other large carnivores which habituallykill quantities of heavy game are greatly influenced in a definiteway by the development of the principal muscles used in gripping,holding, tearing, biting, and shaking. If the animals are capturedwhen young and reared in confinement these particular muscles arelittle developed and the bone at the region of origin or insertion islittle changed by their influence. The bones then retain certaincharacteristics of juvenility and develop along wholly different butuniform lines from that of the wild-reared animal.Changes in the skull which would be accepted as of " specific " orpossibly of " generic " value in wild animals from different regionsare thus produced in the life of a single individual within from fiveto seven or eight years, almost as rapidly as if by " mutation."The primary object of this paper is to call attention to a definitecase of structural modification by habit.^ No idea of extensive specu-
1 The value of evidence derived from this case over that furnished by experimentalmutilation of young animals can easily be appreciated. Nevertheless experiments suchas those recorded by Anthony and others, like the removal of the greater part of the
NO. 2196. EFFECTS OF ENVIRONMENT ON LIONS?HOLLISTER. 191lation on its meaning or the possible value of the records in the studyof evolution is contemplated. The opportunity for such speculation,however, is unlimited, and the temptation is great. This remark-able change has taken place in the lions under artificial treatment.Might some such a change not happen in a state of nature? Atnumerous times in geologic history whole groups of animals havebecome extinct. In fact, this is the rule, and only a few of the typesknown from fossil remains have left living descendants. If all theimgulate mammals of Africa or in some one extensive region wereswept away in a few years by a plague like the rinderpest, wouldthe lion die out, or would he completely change his habits in onegeneration and become a feeder on mice, squirrels, birds, and fruit?In the latter case, would not the enforced disuse of the powerfulmechanism for the destruction of zebras, hartebeest, and larger gameproduce in one generation, as with the park lions, a type of skullwholly different from that now known in a state of nature?One can easily believe that if the ordinary wild lion skulls wereknown only from Miocene deposits and the specimens were com-pared with the MciVIillan lion skulls, they might be regarded as rep-resenting the ancestor of the latter. The great change would natu-rally be regarded as the result of slow variation continued over thatlong period of time.The use of zoological park material in the description of new formsof mammals should be discouraged. New names should never bebased on animals in parks or on skins and skulls of specimens whichhave lived long in captivity.Relative dimensions (ratio of length to breadth) of skulls is shownby the McMillan lions to be easily changed by habit or environment.Great weight has often been placed on the ratio of length to breadth,as a deep-seated character. Paleontologists, especially, value suchdifferences much higher than do workers in recent mammals whohave access to large series of closely related subspecies and are fa-miliar with the variations they exhibit in this respect. The surpris-ing and uniform differences in this regard between the McMillanlion skulls and the skulls of wild-reared examples of Felis leo mas-saica are, nevertheless, a revelation to all mammalogists who haveseen the specimens.left temporal muscle of a puppy at birth and the subsequent dissection of the animalat or near maturity, have shown the importance of the study of the action and growthof the muscles, exercised by peculiar habit, in the formation of species. (See especiallyAnthony, Bull. Sci. Anthr. Paris, ser. 5, vol. 4, 1903, pp. 119-145, figs. 1-11. Anthonyand I'ietkiewicz, C. R. Acad. Sci., vol. 149, 1909, p. 870, and other papers by the sameauthors.)
192 PROCEEDINGS OF THE NATIONAL MUSEUM. VOL. 5S.
Measurements of skulls of lions.MALES.
Loi^lJty or history.
Wild-killed massaica.Kapiti StationDoUlu StationUlukenia HillaNairobiLaikipiaPark-reared.
"McMillan lion"Do"Richardson lion"'..."Menelik lion"?"Abyssinian lion"^...
182297 322j 373182332 328i 372182307 3241....182313{.... ....155443 335 373163328 316 337
197944 309199707 32538246 332144054 296[ 335174639 308i 333
248! 135228i 138230 142236234233
345 261363 264366
135133
146152277i 139255! 1322461 128
S2
?SB
8.67.38.77.99.38.2
.2 " I .-2
a! ^s
C C3
8.015.8135.85.511.2 30.06.514.2 31.37.012.2129.54. 0,14. 4131.96.016.0133.2
78 12. 4 10. 5 25. 7 31. 480114.811.5 29. 136.97513.012.5120.5 30.870i20.5|18.1|24.2,29.471112. Sill. 5127. 2 31. 6
112111
107108
116120124117112
257253249244256235
248260248236233FEMALES.
Wild-killed massaica.Kapiti StationDoDoDoDoUlu StationDoDoWamiHillKitangaPark-reared.
"McMillan lioness". .
.
Do
182293
NO. 2196. EFFECTS OF ENVIRONMENT ON LIONS?SOLUSTER. 193
EXPLANATION OF PLATES.Plate 22.(One-third natural size.)Skull of wild-killed adult male Felis leo massaica. U.S.N.M., Cat. No, 155443
;
near Nairobi ; British East Africa, 1908 ; collected by John Jay White.Plate 23.(One-third natural size.)Skull of park-reared adult male Felis leo massaica. U.S.N.M., Cat. No. 199707;captured as small cub near Nairobi, British East Africa ; died in Nat. Zool. Park,Washington. Plate 24.Skulls of adult female Felis leo massaica (one-third natural size).Upper. Park-reared; U.S.N.M., Cat. No. 199524; captured as small cub nearNairobi, British East Africa ; died in Nat. Zool. Park, Washington.Lower. Wild-killed; U.S.N.M., Cat. No. 182326; Kapiti Station, British EastAfrica, 1911 ; collected by Paul J. Rainey.Plate 25.Skulls of adult male Felis leo massaica, occipital views (reduced; same scale).Upper. Wild-killed; U.S.N.M., Cat. No. 155443; near Nairobi, British EastAfirca ; collected by John Jay White.Lower. Park-reared; U.S.N.M., Cat. No. 199707; captured as small cub nearNairobi, British East Africa ; died in Nat. Zool. Park, Washington.77403?Proc.N.M.vol.53?17 13 .


U. S. NATIONAL MUSEUM PROCEEDINGS, VOL. 53 PL. 22
Skull OF Wild-Killed Adult Male Feus leo massaica.For explanation of plate see page 193.
U. S. NATIONAL MUSEUM PROCEEDINGS, VOL. 53 PL. 23
Skull of Park-Reared Adult Male Felis leo massaica.For explanation of plate see page 193.

U. S. NATIONAL MUSEUM PROCEEDINGS, VOL. 53 PL. 24
Skulls of Park-Reared ' Upper) and Wild-Killed (Lower) Lionesses.For explanation of plate see page 193.

U. S. NATIONAL MUSEUM PROCEEDINGS, VOL. 53 PL. 25
-'':m
Skulls of Wild-Killed (Upper) and Park-Reared (Lowers Lions^For explanation of plate see page 193.