288 dr, t. s. cobbold on human entozoa. [nov. 25, 



11. Remarks on all the Human Entozoa. By T. Spencer 

 CoBBOLD, M.D., F.L.S., Lecturer on Comparative Ana- 

 tomy, Zoology, and Botany at the Middlesex Hospital. 



At the recent Cambridge Meeting of the British Association for 

 the Advancement of Science, I adduced the following argument in 

 favour of a more extended prosecution of experimental research in 

 the department of human helminthology : — " As man is infested by 

 a great variety of internal parasites, and some of them prove exceed- 

 ingly troublesome, it is evident that a large amount of practical good 

 would ensue if we were more perfectly informed respecting the origin 

 and economy of these creatures ; for not only are our personal inter- 

 ests directly affected by their intrusion, but we also suifer indirectly 

 from the injury and destruction they occasion amongst our domesti- 

 cated animals. At least thirty well-marked forms have been de- 

 scribed as infesting the human body ; and although most of the 

 species are comparatively rare, yet a considerable number are exceed- 

 inglv common in occurrence, and likewise often prove numerically 

 abundant in one and the same individual." 



This argument was supported by a reference to certain recently 

 ascertained facts, a more particular account of which, combined 

 with the results of my own inquiries, I now submit to the consider- 

 ation of the Zoological Society. 



In the subjoined list I only record those which are perfectly di- 

 stinct forms, and therefore probably good species. Many forms 

 which were at first supposed to be distinct will be found in the 

 synonymy placed at the head of each comment where the species is 

 separately considered. The larvae are noticed under the titles of the 

 adults to which they are either known or presumed to be respectively 

 referable. This method is followed even in cases where the adult 

 condition is not known to occur in the human body or in any other 

 " host : " thus, for example, the Gysticercus acanthotrias is placed 

 under Taenia acanthotrias, although the mature tapeworm at present 

 remains unknown : — 



Human Entozoa. 



1. Fasciola hepatica, Linnaeus. 



2. Distoma crassum, Busk. 



3. ' lanceolatum, Mehlis. 



4. ophthalmobium, Diesing. 



.5. heterophyes, Siebold. 



6. Bilharzia hcematohia, Cobbold. 



7. Tetrastoma renale, Delle Chiaje. 



8. Hexathyi'idium pinguicola, Treutler. 



9. venarum, Treutler. 



10. Ascaris lumbricoides, Linnaeus. 



1 1 . mystax, Rudolphi. 



12. Trichocephalus dispar, Rudolphi. 



13. Trichina spiralis, Owen. 



14. Filaria medinensis, Gmelin. 



