NEW ASEXUAL TAPEWORM. 847 



cavities lodging many, perhaps most, of the eggs. The present 

 species is, as it were, a stage beyond that exhibited by Anoplo- 

 tcenia dasyuri. As is well known, the imbedding of the eggs in 

 the parenchyma is not a novelty ; for Oochoristica is a genus 

 which is largely characterised by this very feature, though in 

 this case the eggs are imbedded singly and there are not the 

 heaps of eggs seen in the present species and perhaps in Ano- 

 plotcenia. In Anoplotcenia, however, the masses of eggs are 

 usually in cavities of the uterus. In both Oochoristica and Ano- 

 plotcenia, however, the scattered eggs are limited to the medullary 

 region. But the peculiarity of the species with which I am 

 dealing in the present paper is also known in other forms. Clerc * 

 has figured eggs in the cortical region in a species of Dilepis. 



I have some reason to think that the scattered eggs lie in 

 the interstices of the network forming the ground-tissue of the 

 w^orm ; but in any case eggs were also seen lying in larger 

 circular cavities. I believe that these cavities (shown in text- 

 fig. 120) are not the remains of a uterus. They are, as it 

 appears to me, to be directly compared with similar spaces to be 

 seen in mature (but less mature than in the present instance) 

 segments of Inermicapsifer, where I have described and figured 

 them t. In this latter case I was able to bring forward some 

 positive evidence to show that the spaces in question were not, 

 and could not be, the isolated series of chambers left by a 

 vanishing uterus. In the worm with which I am dealing in the 

 present communication I am unable to furnish any of those 

 proofs of the nature of the cavities in question. I can merely 

 point out their general similarity to those of Inermicapsifer. 



Although there were no traces of gonads like those of other 

 tapeworms in this region of the body, I have succeeded in dis- 

 covering what I regard as undoubtedly the generative tissue. 

 The medulla was packed with ripe ova, which, as already said, 

 stray into the cortical layers lying between the bundles of 

 muscles. But at the line of junction of the cortex and medulla 

 and lying in the latter is a continuous mass of tissue with 

 interspersed nuclei, in and just outside of which eggs in various 

 stages of development are to be seen. This is, as I think, 

 undoubtedly to be regarded as a continuous layer of gonadial 

 tissue. I cannot see any other obvious explanation of it. It is 

 clearly totally unlike the ground-tissue of the tapeworm's body 

 and forms a solid mass with darkly staining nuclei. Its associa- 

 tion with developing ova seems to be final in the matter of 

 argument. It is, however, possibly the case that this gonadial 

 tissue is wholly or in part the origin of spermatozoa also ; for 

 testes like those of other tapeworms were not found in the 

 present species. I have, however, no evidence of the presence of 

 spermatozoa. The tissue itself is — save where developing ova 



* Rev. Zool. Suisse, t. xi. 1903, pi. xi. figs. 75, 76. 



+ P. Z. S. 1912, p. 588, text-fig. 77. For the opposite view, see Janicki, Denksclir. 

 Med.-Nat. Ges. Jena, xvi. (1911) p. 381, pi. xiv. figs. 25-27. 



