PROCEEDINGS OF THE UNITED STATES NATIONAL MUSEUM
issued iMr^lVvA- \BM>u ^H '^*
SMITHSONIAN INSTITUTIONU. S. NATIONAL MUSEUM
Vol. 105 Washington: 1955 No. 3351AN ANATOMICAL STUDY OF THE PEREGRINE MEGASCO-LECID EARTHWORM PHERETIMA HUPEIENSIS IN THEEASTERN UNITED STATES ?
By William C. Grant, Jr/
Pheretima (Perichaeta) hupeiensis was first described by Michael-sen (1895) from a specimen collected at Shi-hui-yao near Wuchang,Hupei Province, China. Since then the species has been recordedfrom a number of localities in China, Korea, and Manchuria. Thefirst verified report of P. hupeiensis in the United States is given byChen (1933) from a specimen collected at Philadelphia, Pa.Gates (1935) reports that the species was discovered by Dr. W. R.Walton of the U. S. Department of Agriculture on a golf course nearCatonsville, Md., in 1935. A specimen collected at Washington,D. C, is also reported by Gates. Numerous reports from golf linksin the mid-1 930's of an exotic earthworm were probably concernedwith P. hupeiensis. Its outbreak in Westchester County, N. Y.,and in Fairfield County, Conn., initiated a control program by theConnecticut Agriculture Experiment Station, as the large number ofcastings deposited by the worms on golf greens of the area wasbecoming a serious problem. Chen (1933) suggests that the species
' Representing a portion of a dissertation submitted in partial fulfillment ofthe requirements for the degreeof Doctor of Philosophy at Yale University.? Department of Zoology, Dartmouth CoUege/Hanover, N. H.338103?55 49
50 PROCEEDINGS OF THE NATIONAL MUSEUM voi.. loswas introduced into the United States in shipments of nursery stock,and Schread (1952) beheves that human agency alone can accountfor its present distribution through the medium of turf transportsfrom one golf course to another.The anatomical study presented here represents the first phaseof an investigation that has covered physiological and ecologicalproblems as well. The anatomy of the worm has been reexaminedwith special reference to variation in size and form, and only thosemorphological characters are described in detail where they varyfrom the descriptions of other workers. Bahl's (1950) memoir onthe Indian earthworm Pheretima posthuma has been an extremelyvaluable reference. Specimens of P. hupeiensis used in the presentstudy have been deposited in the U. S. National Museum, Washington,D. C.Appreciation is expressed to Dr. Roger B. Friend, Dr. G. E. Pick-ford, and Prof. G. E. Hutchinson for their counsel during the courseof this study.Methods: All measurements and dissections were made on speci-mens swept from the greens of the Pelham Country Club, Pelham,N. Y., on July 7, 1949, or on specimens collected from the nurseryplot at the same location on various occasions between July andOctober 1952. Because of the differential contractility of anesthetizedindividuals, all measurements of width and length were made onspecimens preserved in the field in 4 percent formalin, in which it washoped that the degree of contraction would be uniform. Widthswere taken with calipers to the nearest 0.5 mm. in the region of theworm just posterior to the male pores and genital papillae.Before sectioning in the laboratory the animals were kept on dampcheesecloth or in aerated tap water for several days in order to allowevacuation of the gut. Worms were then fixed in Petrunkevitch'ssublimate fluid for 24 hours, sectioned, and stained with hematoxylinand eosin. Whole mounts of spermathecae, prostates, etc., weremade of organs fixed in Petrunkevitch's fluid and cleared in amyl-acetate. In order to examine the internal sexual structures it wasnecessary to reverse the normal procedure and dissect worms from theventral side.Before analysis all specimens to be examined were placed in thefollowing categories:1. Mature. Clitellum fully developed.2. Semimature. Clitellar segments distinct but with all setae and dorsalpores still visible.3. Immature. Clitellar segments not differentiated. Male pores and genitalpapillae well developed.4. Juvenile. No differentiation of clitellar segments and with male poresand genital papillae lacking or indistinct.
EARTHWORM PHERETIMA HUPEIENSIS?GRANT 51Color: Pheretima hupeiensis varies in life from pale green to deepolive. Occasionally it is of a deeper hue anteriorly, although this isby no means a characteristic condition. A distinct purple or blackline is apparent on the dorsal midline extending from the posteriormargin of the clitellum to the last segment, interrupted interseg-mentally by the dorsal pores. The clitellum in the mature conditionis a brilliant ivory, while the clitellar regions of the semimature arealmost black in color. With the exception of the clitellum there isapparently no deepening of color with age. This description is innear agreement with that of Chen (1933) and that of Schread (1952).The specimens from the Pelham collection seldom showed the pro-nounced difference in coloration from the dorsal to ventral surfacesas described by Chen for worms of the Yangtze Valley, China. Hisdescription of animals with a light chocolate clitellum was probably ofindividuals past their sexual prime, as this color is quite common justbefore clitellar degeneration.Size : In the preserved specimens from Pelham, the size varies from89 to 22 mm. in length, and from 5.5 to 1 mm. in mdth. The meanlengths and widths for each of the four categories described above andtheir standard deviations are shown in table 1. The relationshipbetween length and width is presented graphically in figure 1. Theline representing the regression of width on length indicates a constantisometric relationship between length and diameter. In the equationW=a+6L the values of the constants a and 6 are 0.18 and 0.058, re-spectively. The correlation coefficient of 0.77 is highly significant.The analysis justifies the earlier assumption that worms preservedunder standard conditions are uniformly contracted.In specimens from Szechwan Province, China, Chen (1931) gives asize range from 70 to 130 mm. in length, and 3 to 6 mm. in diameter,while his 1933 Yangtze Valley description mentions worms as long as222 mm. Kobayashi (1938) gives lengths of 61 to 150 mm. withwidths up to 5 mm. in specimens from Korea. The type specimendescribed by Michaelsen (1895) from Hupei Province, China, meas-ured 40 mm. in length with a diameter of 3.5 mm. A specimen de-scribed by Gates (1935) from Washington, D. C, was 70 mm. long and3 mm. wide.It would be extremely difficult to draw any definite conclusions fromthese figures, for, with the exception of Gates' specimen it is not knownunder what conditions the worms were measured, nor is there an indi-cation of their state of maturity. Nevertheless, there is some indica-tion that on the Asiatic mainland the species is larger than the pere-grine population of the United States. The relation of width tolength suggests that the figures of Chen and Kobayashi show worms
52 PROCEEDINGS OF THE NATIONAL MUSEUM vol. losin a greater state of attenuation than my formalin specimens. Inorder to obtain some idea of the differences the length-width relation-ship may be expressed in the form of an index (w/lXlOO). Meanvalues for the Pelham population ranging from juvenile to mature are6.2, 6.2, 5.8, and 6.0. If the longest worm is correlated with the great-est diameter and the shortest with the smallest the following indices
Figure 1.?Relation of length to diameter in specimens of Pheretima hupeiensis preservedin 4 percent formalin.
are obtained for the Asiatic specimens: Chen 4.3-4.6, Kobayashi 3.3.These forms appear more slender than the Pelham stock.Avel (1929) has shown that size variation in AUolobophora is de-pendent on nutrition, and Pickford (1937) says that because of thisfactor it would be impossible to indicate a size range for a species thatwould have taxonomic significance. This is further substantiated bythe apparent larger size of the oriental population of P. hupeiensis.Weight: A group of 162 worms collected from the nursery plot atPelham on Aug. 22, 1952, were classified into the four categories ofmaturity and weighed. The range was from 898 mg. for a matureworm to 41 mg. for a juvenile. The means and their standard devia-tions are listed in table 1. The mean value for juveniles is 103 mg.,with no weights above 223 mg. being recorded for this category. It isprobable that somewhere between these values the majority of thepopulation will develop prominent male papillae. The figures for
EARTHWORM PHERETIMA HUPEIENSIS?GRANT 53mature individuals give a mean of 562 mg. with a minimum weight of302 mg., and it is between these values that most worms become fullyclitellate. As the semimature and immature categories are con-tinually shifting, it would be difficult to analyze them satisfactorilyunless weights were taken at frequent intervals from populationsamples distributed over a period of several years. Such a project isvery important, but would have to be carried out on a more readilyavailable species of worm than P. hupeiensis, which has been sub-jected to routine extermination over its recorded range in the UnitedStates.Segments: Michaelsen (1895) described P. hupeiensis as having 129segments and again (1899) as having segments ranging in numberfrom 119 to 132. Chen (1933) gives numbers from 110 to 128, andKobayashi (1938) indicates a range of 97 to 132 for his Korean col-lections. Counts made on preserved material from the Pelham col-lection show no correlation between the degree of sexual maturity andnumber of segments. The average for 22 juveniles was 125 segments,and for 39 adults it was 126, with a range of 119 to 130 for the entireseries studied.The whole problem of whether or not earthworms continue addingsegments during life has been discussed by Gates (1948). After astudy of a number of megascolecid, lumbricid, and glossoscolecidspecies he concludes that postembryonic growth generally involvesthe production of new segments, although segment production doesnot take the same form in every case nor is it uniform throughoutthe three families. Because no specimen of P. hupeiensis has beenfound to date that can definitely be regarded as newly hatched, it isimpossible to state whether new segments are added after hatching.However, since juveniles and fully mature specimens possess aboutthe same number of segments, few if any additions are made afterthe worms have attained a length of 35 mm. Careful dissection ofjuvenile specimens in the region of the anal segment revealed nothingthat suggested that this segment was not fully differentiated.Setae: The numerous setae, which are weakly sigmoid in shape andabout 0.2 mm. in length, are perichaetous, as each segment has anequatorial band of setae passing around it. Michaelsen found 72setae on segment 25, and Chen (1933) gives numbers ranging from68 to 88 for the same segment with 14 to 22 between the spermathecalpores of segment 8 and 10 to 16 between the male pores on segment 18.Gates (1935) records 85 setae on segment 20, and 18 on segment 18between the male pores.In the specimens of P. hupeiensis in the Pelham collection, setalnumbers averaged about 8 between the spermathecal pores of segment8, with a range from 4 to 13; 12 between the male pores of segment 18,
54 PROCEEDINGS OF THE NATIONAL IMUSEUM
with a range of 8 to 16; and 79 around the drcumference of segment30, with a range of 74 to 84 (table 1). In mature specimens a fewsetae were usually seen on the ventral surface of the clitellum. Thewide range in setal number is due in part to the fact that setae arecontinually being lost and replaced.Prostomium: The small prostomium overhangs the mouth and isepilobous, according to the terminology of Stephenson (1930), inthat it is well subdivided from, but with its posterior portion extend-ing into, segment 1. In preserved specimens the prostomium is with-drawn and not easily examined.Dorsal pores: In 39 mature specimens collected at Pelham thefirst dorsal pore appeared on intersegmental fm-row 11/12 and, in allobservations made since, this has been found to be a very constantcharacter. Michaelsen (1895, 1899) notes the first dorsal pore onintersegmental furrow 12/13, as does Gates (1935). However, Chen(1931, 1933) and Gates (1939) record the first dorsal pore on 11/12.Dorsal pores are present in the dorsal midline at all intersegmentalfurrows beginning with 11/12 in the Pelham specimens, although theymay be obscured in fm-rows 14/15 and 15/16 by the clitellum.It is through the dorsal pores that coelomic fluid is ejected when theworm is UTitated. In P. hupeiensis the peculiarly pungent odor ofthe coelomic fluid, described by Gates (1935) as being simflar to thatof "carrots freshly dug," is an important diagnostic character.Male reproductive system: The male reproductive system isholandric. Paired testes are situated in segments 10 and 1 1 , attached tothe posterior face of septa 9/10 and 10/1 1 close to the ventral nerve cordand directly in front of their corresponding spermiducal funnels. Thelatter have highly folded, ciliated margins, each passing immediatelyinto a vas deferens in the following segment. Two pairs of largeseminal vesicles are located in segments 11 and 12, probably arising as
Abbreviations used on figures
ac. gl accessory glandamp ampullaant. lo.. anterior loopbu buccal chambercae caecumcm circular musclediv diverticulumd. V dorsal vessele epidermisgizz gizzardht heartint intestine
lat. oes. lateral oesophagealv. vessel1. gl lymph gland1. m longitudinal musclem. s muscle strando ovaryoes oesophaguso. f oviducal funnelph pharynxp. gl prostate glands septa 11/12
s. f spermiducal funnel
sp spermathecaesu. i. v_- supraintestinalvessel
s. V seminal vesiclest testist. s testes sacsV. d vas deferensV. n ventral nerve cordV. V ventral vesselw. t. s._ wall of testis sac
EARTHWORM PHERETIMA HUPEIENSIS?GRANT 55
septal pouches from septa 10/11 and 11/12. Each communicates di-rectly with and receives the spermatozoa of the segment in front.The seminal vesicles when full of developing sperm are large and dis-tended, passing dorsally around the gut to the dorsal blood vessel.
su.ty
sy.
latoesM
Figure 2.
?
Pherethna hupeiensis; semidiagrammatic view of a section through segment 11showing the annular shape of the testes sacs. For explanation of abbreviations see facingpage.The small, narrow vesicles described by Chen (1933) were undoubt-edly not seasonally mature or had been shrunk during preservation.In P. hupeiensis the testes, funnels, and seminal vesicles of segments10 and 11 and the seminal vesicles of segment 12 are partitioned fromthe coelomic cavity by large, thin-walled sacs. These are commonlycalled testis sacs, but Kobayashi (1938) has questioned the propriety
56 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 105
of calling the posterior sac by this name as there are no testes presentin segment 12. He proposes terming this structure a "membranoussac." The testis sacs of segments 10 and 11 are very large, extendinglaterally almost to the body wall and medially to the esophagus toenclose the male organs and hearts of their corresponding segments.Sections of the Pelham specimens show that the sacs are unpairedand annular, as each is continuous dorsally and ventrally with itsmember of the opposite side (fig. 2) . This is in agreement with Chen(1933). Gates (1935, 1939) describes the sacs as U-shaped with nodorsal connection, and it is possible that a degree of variability mayexist as to the shape of these structures. The membranous sac ofsegment 12 is similar in structure to the testis sacs, but only enclosesthe seminal vesicles of its segment.The vas deferens from each testis extends posteriorly to form a closecontact with the other spermatic duct of its side in segment 13. Al-though the two ducts maintain their individuality throughout, thiscan only be seen in sectioned material. The spermatic ducts passposteriorly, lateral to the nerve cord, until they communicate with thecommon prostatic-spermatic ectal duct.The pau- of prostate glands, lying in segments 17 to 19 and pene-trating septa 17/18 and 18/19, are large flattened structures usually com-posed of two or more irregular lobes (fig. 3). In life they are milkywhite in color, and bulk large during sexual maturity so that they canbe seen as large masses through the body wall of fully clitellate speci-mens. From the two major lobes ducts emerge and pass ventrallyto unite with the two spermatic ducts of a side in the common prostatic-spermatic ectal duct. This heavy structure coils once and opensthrough the body wall at the male pore in segment 18. Accessoryglands are located just anterior and posterior to the base of the aboveduct in segments 17 and 19, opening on the external genital papillae.Externally the male pores open ventrally on small, raised tuberclesin line with the setae of segment 18 (fig. 4,a). The two pairs offlattened genital papUlae are situated close to the intersegmentalfurrows 17/18 and 18/19 just medial to the male pores. In all of thespecimens from Pelham and in the accounts of other authors novariation in the appearance and location of the male reproductiveorgans, with the exception of the testis sacs, has been noted.If Female reproductive system: The ovaries are situated on theposterior face of septum 12/13 just lateral to the ventral nerve cord.They are white in color and are composed of a large number of digitalprocesses arranged so as to resemble a fan. The paired oviducalfunnels are large, convoluted structures in segment 13 facing theovaries and communicating posteriorly with the short oviducts thatpass through the body wall in segment 14 to the single female pore
EARTHWORM PHERETIMA HUPEIENSIS?GRANT 57(fig. 3), This pore opens on a raised circular papilla in the ventralmidline of segment 14 just posterior to intersegmental furrow 13/14(fig. 4,a).The clitellum consists of a smooth, slightly swollen girdle in seg-ments 14 to 16 that passes uniformly around the body. The positionof this structui'e is constant.In P. hwpeiensis the typical arrangement of the spermathecae is asfollows: The first pair is located in segment 7, while segment 8 con-tains the posterior two pairs (fig. 3). Each spermatheca is composedof a long, oblate ampulla, which is not clearly differentiated from its
aeg/.Figure 3.?Diagram of the reproductive system of Pheretima hupeiensis. For explanationof abbreviations see page 54.duct. From the base of the duct a long diverticulum extends forabout twice the length of the ampulla, terminating in a small, sphericalchamber. Below the chamber, the lumen of the diverticulum ishighly convoluted for about half its length before it straightens intoa tube leading directly to the duct of the ampulla (fig. 4,6). Thespermathecae described by Chen (1933) as spatulate and highlywrinkled were obviously in a collapsed condition.Although many animals show the typical arrangement describedabove, it is quite common to find individuals with an entire sperma-theca transferred to an adjacent segment. However, no more norless than three pairs of spermathecae have been described in a single
58 PROCEEDINGS OF THE NATIONAL MUSEUM vol. iob
specimen. The external order of the spermathecal pores, which arelocated by pairs just posterior to the intersegmental furrows 6/7, 7/8,and 8/9 on either side of the ventral midline, is constant regardless ofinternal conditions (fig. 4,a). Michaelsen (1895) noted only twopairs of spermathecae in the type from Hupei Province, but in 1899he redescribed the specimen as possessing three pairs. No variationin the spermathecal number has been described by other investigators.Septa: Only the first three septa are lacking in P. hupeiensis.Septum 4/5 is extremely fine, while septa 5/6 to 8/9 are heavy andmuscular as are those of the genital segments, but to a lesser extent.Bahl (1950) noted that in Pheretima posthuma all septa past 14/15 areperforated by numerous small apertures surrounded by muscularsphincters. Careful examination of the septa of P. hupeiensis failedto disclose any such structures other than the septal sphincter sur-rounding the ventral nerve cord foramen.Digestive tract: The mouth opens into a small buccal chamberlocated in segments 1 and 2, and is Uned with columnar epitheliumsurrounded by a heavy mass of muscle. The pharynx of segments3 to 5 is characterized by a dorsal mass of muscular tissue that servesto compress its lumen dorsoventrally. The dorsal surface of thepharynx is covered with numerous phar3mgeal glands.The oesophagus extends from segment 5 to 16. The gizzard issituated in segment 8. That Chen (1933) describes it in segments8 and 9 may be a result of the fact that the gizzard gives the appear-ance of extending into segment 9 because of the cone-shaped septum8/9 that overlaps it for about half its length. The gizzard is sur-rounded by a thick wall of circular muscle fibers and is bound inter-nally by a cuticle secreted by the gut epithelium. The oesophagusbroadens in segment 9 and continues through segment 13 to its junctionwith the intestine. Examination of the oesophagus indicated that inP. hupeiensis calciferous glands are wanting.The intestine occupies the entire length of the worm beyond septum13/14 to the terminal anus (fig. 4,c). A pair of simple intestmalcaeca appear as lateral projections of the intestinal wall in segment 27,although a few cases observed had the caecum originating in segment28. Those of the type are located in segment 26.Hearts: The paired lateral hearts are located in segments 10 to 13(fig. 4,c). The hearts of segment 10 are very stout and lack commis-sural connections to the supraintestinal blood sinus. The followingthree pau-s join the dorsal and ventral blood vessels and have commis-sural connectives with the blood sinus of segments 11 to 13, and maybe termed lateral-oesophageal hearts to differentiate them from thesimple lateral hearts of segment 10 according to Bahl (1921). In
EARTHWORM PHERETIMA HUPEIENSIS?GRANT 59segment 9 a paii' of heavy but nonpulsating vessels connect the supra-intestinal blood vessel with the lateral-oesophageal vessels on eachside. Two pahs of similar vessels occurring in segments 10 and 11 ofPheretima posthwna are termed "anterior-loops" by Bahl (1921).Excretory system: The excretory system is similar to that ofP. posthuma described by Bahl (1921, 1950). The system is mero-nephric in that it is composed of several types of nephridia, and that
SPERMATHECALPORE
2 PORE
bu. pH inf. d.v.
09 s. Qnilo. SU.I.V. hf. lot OfiS. V. V, V. CQ9.Figure 4. Pheretima hupeiensis: a, external sexual characters; b, a spermatheca; c, digestivesystem and hearts. For explanation of abbreviations see page 54.
60 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 105numerous nephridia are present in most segments. The followingclassification follows that of Bahl (1924, 1926, 1950).The integumentary nephridia are extremely small, ranging from0.25-0.5 mm. in length, and are scattered over the interior face of thebody wall in all but the first two segments. As no collecting funnel ispresent and each nephridium communicates directly to the exteriorthrough its nephridiopore, they are termed exonephric micronephridia.In P. hwpeiensis there are about 175 such micronephridia per segmentin the region posterior to the intestinal caeca.The septal nephridia are distributed over the anterior and posteriorfaces of all septa behind 15/16, close to the body wall. The nephro-stome is well developed, coi:isisting of from 10 to 12 marginal cells com-posing a funnel and sLx closely compacted cells forming the ventral lip.The excretory products, carried by a series of collecting ducts, aredischarged mto the gut. The septal nephridia are classified as entero-nephric meganephridia. There are 70 to 80 such meganephridia persegment in the region just posterior to the caeca.The pharyngeal nephridia, which lack collecting funnels, are entero-nephric micronephridia. They are composed of large masses of inter-connected nephridia scattered over the lateral pharyngeal walls.Excretory products are discharged from the collecting ducts into thelumen of the pharynx.Discussion: In all major respects the Pelham population of P.hupeiensis is in taxonomic agreement with the type specimen as de-scribed by Michaelsen. The first dorsal pore of the type is locatedat intersegmental furrow 12/13, while it was found at 11/12 in all thePelham animals. The pair of intestinal caeca which occur either insegment 27 or 28 in the Pelham worms is recorded in segment 26 ofthe type. Size variations are of course to be anticipated because ofnutritional differences, etc., as is the relation between absolute sizeand the degree of sexual maturity. Segment and setal numbers showa narrow range of variation considering their large numbers. Thespermathecal ampulla and diverticulum may or may not penetrateadjacent septa, but as the position of the external pores is constant,their internal arrangement is of minor importance.The Pelham population shows a high degree of uniformity. Onlythe position of the caeca was subject to meristic translocation and,except in one specimen which possessed a supernumerary female pore,no homoeotic duplications were observed. P. hupeiensis is in closetaxonomic agreement with its genus, its species characters faUingwithin the generic range of variability as given by Stephenson(1930).Diagnostic characters: External: Color pale green to deep olivewith a distinct purple or black line on the dorsal midline extendingfrom the posterior margin of the clitellum to the anal segment.
EARTHWORM PHERETIMA HUPEIENSIS?GRANT 61Preserved animals are light gray and the dorsal line is seldom dis-cernible. Odor pungent. Length 40 to 222 mm.; diameter 1 to 6mm.; weight 320 to 898 mg.; segments 97 to 138 in number. Firstdorsal pore on intersegmental furrow 11/12 and 12/13. Prostomiumsmall and epilobous. Perichaetous, the setae varying in number from4 to 22 between the spermathecal pores on segment 8; 8 to 18 be-tween the male pores on 18; 66 to 88 on 25; 74 to 84 on 30. Clitellumsmooth, white and annular on segments 14 to 16. Male pores onTable 1.?Means for the various measurements made on the ana<07ny o/ Pheretimahupeiensis NumberCharacter
62 PROCEEDESrGS OF THE NATIONAL MUSEUM vol. 10513, the pair in segment 10 being stout and lacking commissural con-nectives. Excretory system meronephric. Exonephric integumen-tary micronephridia in all but the first two segments; enteronephricmeganephridia on all septa behind 15/16 ; enteronephric micronephridiaon the lateral walls of the pharynx. Male reproductive system holan-dric. Paired testes and spermiducal funnels in segments 10 and 11;paired seminal vesicles in segments 11 and 12. Testes and funnels ofsegment 10 and testes, funnels, and seminal vesicles of segment 11enclosed in large membranous testis sacs that may be annular or U-shaped. Seminal vesicles of segment 12 enclosed in a membranoussac. Prostate gland well developed in segments 17 to 19, with alarge coUed prostatic-spermatic ectal duct in segment 18; accessoryglands small, located near end of duct in segments 17 and 19. Onepair of ovaries and oviducal funnels in segment 13. Internal ar-rangement of spermathecae variable; typically the first pair is locatedin segment 7, whUe segment 8 contains the posterior two pairs.Spermathecal ampulla long and oblate; diverticulum twice the lengthof ampulla, its coiled duct terminating in a small round chamber.Type: Perichaeta hupeiensis Michaelsen (1895), Hambiu-g Museum.Summary: The anatomy of Pheretima hupeiensis Michaelsen, amegascolecid earthworm indigenous to the far east, has been rede-scribed on specimens collected in Westchester County, N. Y., whereit occurs as a peregrine. A constant isometric relationship existsbetween length and width when worms are preserved under standardconditions. The population shows a high degree of uniformity.The only characters showing variation are the intestinal caeca, whichmay arise in segments 27 or 28, and the spermathecae, which areconstant in number but vary in their position relative to the adjacentsepta.
Literature citedAVEL, M.1929. Recherches exp^rimentales sur les caractferes sexuels soraatique deslombriciens. Bull. Biol. France Belgique, vol. 63, p. 149.Bahl, K. N.1921. On the blood-vascular system of the earthworm Pheretima and thecourse of the circulation in earthworms. Quart. Journ. Micr. Sci.,vol. 65, pp. 349-393.1924. On the occurrence of the "enteronephric" type of nephridial systemin earthworms of the genus Lampite. Quart. Journ. Micr. Sci.,vol. 68, pp. 67-99.1926. The enteronephric system in Woodwardia with remarks on thenephridia of Lampite dubius. Quart. Journ. Micr. Sci., vol. 70,pp. 113-134.1950. Pheretima, the Indian earthworm, in The Indian zoological memoirson Indian animal types, I (ed. by Bahl), ed. 4, 84 pp.Chen, Y.1931. On the terrestrial Oligochaeta from Szechuan. Contr. Biol. Lab. Sci.Soc. China, vol. 7, pp. 117-171.1933. A preliminary survey of the earthworms of the lower Yangtze Valley,Contr. Biol. Lab. Sci. Soc. China, vol. 11, pp. 109-121.Gates, G. E.1935. New earthworms from China, with notes on the synonymy of someChinese species of Drawida and Pheretima. Smithsonian Misc.Coll., vol. 93, No. 3, 19 pp.1939. On some species of Chinese earthworms, with special reference tospecimens collected in Szechwan by Dr. D. C. Graham. Proc.U. S. Nat. Mus., vol. 85, pp. 405-507.1948. On segment formation in normal and regenerative growth of earth-worms. Growth, vol. 12, pp. 165-180.KOBAYASHI, S.1938. Earthworms of Korea, I. Sci. Rep. Tohoku Teikoku Daigaku, ser.4, vol. 8, pp. 89-170.MiCHAELSEN, W.1895. Zur Kenntnis der Oligochaeten. Abh. Naturw. Hamburg, vol. 13,pp. 35-36.1899. Terricolen von verschiedenen Gerbieten der Erde. Mitt. Naturh.Mus. Hamburg, vol. 16, pp. 6-8.PiCKFORD, G. E.1937. The acanthodriline earthworms of South Africa, 612 pp.SCHREAD, J. C.1952. Habits and control of the oriental earthworm. Connecticut Agr. Exp.Station Bull. No. 556, pp. 5-15.Stephenson, J.1930. The Oligochaeta, 978 pp. 63
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