310 THE ANATOMY OF CESTODES. 



This is a copulatory organ, which is introduced into the female open- 

 ing, 1 and indeed generally into that of the same joint (van Beneden, 

 Leuckart), and being provided with a fringe of backward-directed 

 bristles or points, is specially adapted to effect a firm union. As a 

 rule, however, this cirrhus is not an independent organ, but the more 

 or less independently developed anterior end of the so-called muscular 

 " cirrhus-pouch." This is attached to the male opening, and consists 

 of a conspicuous structure of cylindrical or ampulla-like form, which is 

 completely surrounded as far as the point mentioned by the body- 

 parenchyma, 2 with which it is also connected by retractor and pro- 

 tractor muscular fibres. In a certain sense, however, the cirrhus- 

 pouch appears to be also a part of the seminal duct ; at all events, 

 the latter appears to be in direct continuity with it. Its internal 

 cavity may be observed running along the whole length of the cirrhus 

 pouch as a distinctly marked passage, with pretty thick cuticular 

 covering; and one even feels convinced that it is only the highly 

 developed muscular wall of this passage which forms the cirrhus- 

 pouch, and that it only appears to be a special structure because the 

 other far greater part of the seminal duct is destitute of this covering. 

 But on closer examination it is soon seen that the cirrhus-pouch 

 does not consist of a simple layer of muscles, but rather of a muscular 

 external wall and of an internal mass, which is partly, it is true, X)f a 

 muscular nature, but consists principally of a clear connective sub- 

 stance. The enveloping layer exhibits fine thickly matted fibres, 

 which sometimes run circularly, or at other times with a more 

 diagonal course, crossing each other and forming a hollow muscle, 

 which is evidently able powerfully to compress the interior mass. In 

 contrast to this, the fibres of the latter have a more longitudinal 



1 Sommer doubts the existence of a special copulation in the Cestodes (loc. cit. t p. 

 507), and only admits an overflowing of the seed into the vaginal opening, which might 

 easily be caused by the pressure of the body after the closure of the genital pore and the 

 shutting off of the general cloaca. This, he says, he directly observed in the case of Tcenia 

 saginata and T. solium. In answer to this, I can only repeat that I have observed just as 

 directly, and in the most distinct manner, an " immissio penit" (Fig. 165) in Tcenia. cchino- 

 coccw*, and that under circumstances which excluded the possibility of confusing it with the 

 overflowing of spermatic masses. Besides this, it cannot be admitted that an organ, which in 

 many species is as long as half the width of the body, and which most obviously possesses 

 all the characteristics of a copulatory organ, should only serve its possessor as an orna- 

 ment. Yet, as the structure of the cirrhus exhibits many varieties, it is quite conceiv- 

 able and possible that the act of copulation is not always effected in the same way. But 

 the above observations of van Beneden and myself are not the only ones which can be 

 adduced against Sommer. Pagenstecher (loc. cit., p. 528) has also observed the copula- 

 tion in Tetrabothrium auricula, but in this case no self-fertilisation took place, but the 

 penis of one joint was sunk into the vagina of another, a few joints distant. 



2 Kahane describes the cirrhus of Tcenia perfoliata as a special organ, situated at the 

 base of a pocket or bell-shaped cirrhus-pouch, from which it protrudes. 



