DE. T. S. COBBOLD ON ENTOZOA. 255 



Further Observations on Enfozoa, with Experiments. By T^ 

 Spenceb Cobbold, M.D., F.L.S., Lecturer on Zoology and 

 Comparative Anatomy, Middlesex Hospital College. 



[Abetract of Paper read Dec. 20th, I860.] 



This communication is designed as a continuation of the author's 

 serial papers on JEntozoa^ two of which have already appeared in 

 the Society's Transactions. 



The first species noticed is Distoma conjunctwn (Cobbold), 

 found infesting the liver of the American Red Fox {Canis fulvus) . 

 Griving an account of its anatomy, Dr. Cobbold closes his 

 description as follows : — " In connexion with the reproductive 

 system, I may notice the circumstance of a pair of these flukes 

 being found sexually united, — an observation so rare,, that it has, 

 I believe, led some to infer that the hermaphroditic flukes were 

 capable of self-impregnation. Even Bilharz's discovery of a Tre- 

 matode specially furnished with a gynaecophoric canal afforded no 

 direct proof of a true sexual function in the androgynous Disto- 

 mata, because in his aberrant form (as obtains also in a few others) 

 the sexes are separate. Many thousands of flukes must have 

 now passed under my examination, and yet this is the first instance 

 in which I have observed a true sexual union ; moreover, I am 

 not acquainted with any similar observation on record, so far as the 

 truly hermaphroditic species are concerned. In the instance now 

 mentioned, the opposed suckers were so firmly adherent, that it 

 was found impossible to detach the animals without breaking them 

 up piecemeal." 



The next species referred to is Pentastoma denticulatum. A 

 minute account is given of its anatomy, and more particularly of 

 the cephalic hooks and their capsules. A careful experiment of 

 the author's, in relation to the question as to whether this animal 

 is the young oi Pentastoma tcenioides, was attended with a negative 

 result. 



The third species commented on, and minutely described, is 

 Tricliocejplialus ajjinis, obtained in the present instance from the 

 caecum of a Giraffe. This parasite had been previously noticed 

 by the author in his paper entitled " Contributions to the Ana- 

 tomy of the Giraffe," published in the ' Proceedings of the 

 Zoological Society of London ' for February 1860. Dr. Cobbold 

 had provisionally recognized it under the title of Tricho«ep]mluH 



