18G2.] DR. T. S. COBBOLD ON HUMAN ENTOZOA. 305 



J'eniiis vesicidaris, Brera. 

 Fintia humana, Weruer. 

 Vesicaria finna suilla, Sclirank, Bay. 

 V. hygroma humana, Schrank, Bay. 

 V. lobata suilla, Fabricius. 



Now that the organization and mode of development of this species 

 is so well understood, it is a matter of regret that the manifest errors 

 of earlier writers are not more carefully excluded from our ordinary 

 manuals of zoology and comparative anatomy. I allude, for example, 

 to such points as the still asserted presence of a mouth and digestive 

 canal in Tceniadce, which cannot be maintained after repeated de- 

 monstrations have clearly proved this view to be erroneous. These 

 falsely so-called alimentary canals constitute the water-vascular sys- 

 tem, and, without entering into minute details, I may here remark, in 

 passing, that they do not form tubes of uniform thickness throughout 

 their course, but present distinct bulbous enlargements at every joint, 

 where the transverse branches are given off. This I have ascertained 

 from the careful injection of a fresh Tapeworm recently sent me from 

 Brighton by Mr. Murray, F.R.C.S.E. 



In regard to the now well-established discovery of Kiichenmeister 

 respecting the development of the common Tapeworm (T. solium) 

 from measly pork, I should not deem it worth while dwelling on the 

 subject, did it not unfortunately happen that a few months back 

 MM. Pouchet and Verrier gave a general denial to the statements of 

 experimental parasitologists respecting the development of Tape- 

 worms from Cysticerci, Those who have read the statement, as pre- 

 sented in the 'Comptes Rendus' (for May 5th, 1862, p. 958), or 

 the translation' of it recently given in the July number of the 

 'Annals of Natural History ' (3rd series, vol. x. p. 77 et seq.), will 

 at once perceive the causes which have led these gentlemen to form 

 conclusions at variance with the experience of at least nine-tenths of 

 the leading helminthologists of the day. As Prof, van Beneden re- 

 marks, they err greatly in supposing that any one regards the Coe- 

 nurus of the sheep as the larva of Tcenia serrata of the dog, seeing 

 that nearly all Continental experimentalists, following Kiichenmeister, 

 have maintained that the Scolex condition of this last-named Tape- 

 worm is unquestionably the Cysticercus insiformis of hares and rab- 

 bits. The researches of Leuckart are especially conclusive on this 

 point ; and my own experiments at Edinburgh in 1856 have left no 

 doubt in my mind as to the correctness of this view. The negative 

 result obtained by MM. Pouchet and Verrier in their last experiment 

 (where they fed two dogs each with a hundred heads of Coenurus 

 cerebralis) certainly seems contradictory as regards the Tcenia coe- 

 nurus ; whilst, on the other hand, it tends to confirm the correctness 

 of our opinion that Coenurus cerebralis and Tcenia serrata have no 

 genetic relation subsisting between them. I, for one, however, shall 

 be glad to repeat these and other similar experiments ; and I may 

 here also remark that it is of very little use for any one not familiar 

 with the species to attempt these inquiries. I strongly suspect, 



Proc. Zool. Soc— 1862, No. XX. 



