106 



THE HELMINTHE- 



§ 103. 



bands are separated by the same number of longitudinal lines, the two nar- 

 rowest of which are above and below; while the others, which are large 

 and riband-like, are on the sides.® 



In the Acanthocephali the transverse muscles are more superficial than the 

 longitudinal,'"' while in the Nematodes and Gordiacei the inverse is true/^* 



§103. 



There are with the Helminthes a great variety of organs for tne move- 

 ments of the body. With the Cystici, Gestodes, and the Trematodes, there 

 are often sucking-cups and cavities ; the first of these are more or less 

 alveolate, being formed of numerous layers of circular and radiated muscu- 

 lar fibres,'^' while the second are only excavations in contractile paren- 

 chyma of the body, and are divided into many chambers by septa, or have 

 very variable lobular appendages.'-' Many of these suctorial organs have, 

 — some at their bottom, others on their borders, hooks with a horny sup- 

 port, by which these animals can firmly attach themselves to objects.*^' 



5 Bojanus, Isis, 1821, p. 186, Taf. III. fig. 49, 

 55, B. (A.icaris lumbricoides). 



ö lu Acanthocephalus the transverse muscles 

 intercommunicate with each other by sliort and nar- 

 row anastomoses, and form a complete ring, which 

 surrounds the longitudinal ones like a large girdle. 

 See, in reference to this, Echinorhynchus gigas. 

 In Echinorhynckus gibbo^'ix these annular mus- 

 cles have been found only above the swelling of the 

 body. 



7 The transverse muscular bundles of the Nema- 

 todes, which are not so closely united as the longi- 

 tudinal ones, do not form closed rings, but produce 

 four segments, which are separated from each other 

 by the crossing over of the longitudinal muscles. 

 At least, this is so In Ascaris lumbricoiuex, i^iron- 

 gy/us gigas, and most 'f the species of this order. 

 Bojanus (Isis,1821, p. 187, Taf. III. flg. 51, 54) 

 and Cloquet (Anat. des Vers intestin. p. ^^5, PI. II. 

 fig. 3) have taken these tra ;verse muscles for 

 vessels ; and Diesing has made the same mistake 

 with the ramified muscles of Cheiracanthus and 

 Ancyracanthus (Ann. d. Wiener Museums II. 

 Abth. 2, Taf. XVI. fig. 1, and Taf. XVIII. fig. 2). 



In Ascaris inflexa, and Fiiaria attenuata, I 

 have seen the transverse muscles ramified in the 

 same manner. In Ascaris spiculigera they have 

 a peculiarity ; their more or less long fibres pass 

 off from the longitudinal muscles at a right angle, 

 and are inserted into one or the other of the two 

 narrow longitudinal rays. In the Gordiacei, the 

 longitudinal layer is not broken by any ray of this 

 kind, but forms continuous tubes which have thin 

 walls and a satin aspect, and where the flattened 

 and riband-like fibres are bound together by their 

 faces, and at the same time anastomose with each 

 other. 



This would at least appear to be so, judging from 

 the net-work with long meshes which is produced 

 by a little traction. I have not found the trans- 

 verse muscles in Gordius ; but in Mermis nigres- 

 cens, there is, under the longitudinal muscular 

 layer, a net-work like the preceding, but with very 

 large meshes. Dujardin appears to have observed 

 it, but he regarded it as connected with the eggs 

 of this worm (Ann. d. So. Nat. XVIII. 1842, PI. 

 YI. fig. 13). 



1 The young Echinococcus, the Coenurus, 

 Cysticercus, and Taenia, have usually upon the 

 cephalic extremity four imperforate cup-like cavi- 

 ties, which can serve only as suckers. It nmst 

 have been an oversight of Nitzsch {Erscli and 

 Gruher\i EncyclopaMlie XII. 1824, p. 95), who 

 regarded these in Taenia as so many oral orifices 



leading into the alimentary canals. It is only with 

 DisComum, Amphistomum, Polystoinum, and 

 other Trematodes, that this sucker, which is sit- 

 uated in front, is perforated at its bottom, and 

 serves also the function of mouth. 



The ventral sucker of Distomum, and that 

 found at the posterior extremity of AmphistomuTny 

 and Polystomum, as well as the numerous analo- 

 gous organs upon the back of Monostomum ver- 

 rucosum, and upon the terminal dilatation of 

 Aspidocotylus mutahilis (Diesing, Ann. d.Wieuer 

 Mus. II. Abth. 2, p. 234, Taf. XV.), are all im- 

 perforate. That upon the posterior extremity of 

 Amphistomum subclavatum, MvXunguiculatum, 

 is remarkable ; it has a small duplicate at its bot- 

 tom, which Diesing (loc. cit. I. Abth. 2, p. 254, 

 Taf. XXIV.) has erroneously regarded as the 

 opening of the genital organs. In Polystomum, 

 six large muscles ])ass from the interior of the body, 

 and are spread upon the convex surfaces of as 

 many suckers, situated at the posterior extremity, 

 and which they properly move during the animal's 

 creeping. 



Ü Upon the head of Bothriocephalus, Tetra- 

 rhynchus, and Anthocephalus, there are two to 

 four simple cup-like fossae ; with Tristomum, 

 Polystomum., and some other Trematodes, there 

 are two on each side of the mouth, and with AxinCf 

 Octobothrium, and Diplozoon, there are two 

 which are subcervical and behind the mouth. 



With Bothriocephalus tumidulus (Bremser 

 Icon. Helminth. Tab. XIII. fig. 21, or Leuckart, 

 Zool. Bruchstücke, lift. I. Taf. I. fig. 4, 5), there 

 are four, which are divided into chambers by many 

 septa ; and with Aspidogaster {Baer, Nov. Act. 

 Acad. Leop. Carol. Vol. XIII. pt. 2, Tab. XVIII.), 

 the whole ventral disc is divided by septa into qua<l- 

 rangular suctorial fossae. The head of Bothrio- 

 cephalus auriculatus has a singular asjiect, due to 

 numerous partly crenulated lobes, which flank its 

 four suckers (Bremser, loc. cit. Taf. XIII. fig. 17, 

 19, and Leuckart, loc. cit. Taf. I. fig. 6-11). A 

 very simple structure is found upon the head of 

 Bothriocephalus tetrapterus, mihi (from the 

 intestine of the seal) ; here the points of junction 

 of the fossae are prolonged' into four triangular 

 lobes, by which the animal can adhere tightly to 

 its object. Holostomum, which lives in the intes- 

 tines of l)irds and mammals, has analogous appen- 

 dages around the cavity which is situated at the 

 anterior extremity, and which it fastens to the 

 intestinal villosities ; see Nitzsch, in Ersch and 

 Gruber\s Kncyclop. III. p. 399, IX. 1822, fig. 1. 



3 This condition of things is found especially in 



