290 DR. T. S. COBBOLD ON HUMAN ENTOZOA. [NoV. 25, 



rejected by Blanchard, is now generally accepted as correct. In 

 other particulars, concerning the mode of distribution of the aqui- 

 ferous vessels, the representations of the French naturalist appear to 

 be trustworthy, and my own injections confirm his statements in all 

 essential points*. Up to the present hour a complete history of the 

 development of this species has not been made out ; but the recent 

 investigations of Van Beneden, Pagenstecher, "Wagener, Filippi, and 

 others enable us to form tolerably accurate conclusions respecting 

 the abode and migrations of its larvse. As, however, T have recently 

 published the results of my investigations on this point in my paper 

 " On the Common Liver Entozoon of Cattle," in the pages of the 

 * Intellectual Observer ' (vol. i. p. 115 et seq.), I need not now reca- 

 pitulate the deductions there recorded ; but I may observe, in passing, 

 that a well-sustained series of researches are still wanting to com- 

 plete the chain of evidence f. The costly nature of these investiga- 

 tions has alone prevented my further prosecution of the necessary 

 experiments. Hitherto, only nine instances have been recorded of 

 the occurrence of this parasite within the human body ; and for par- 

 ticulars respecting these I may also be permitted to refer to my 

 " Synopsis of the Distomidse," in the fifth volume of the Journal of 

 the Proceedings of the Linnean Society. 



2. DiSTOMA CRASSUM, Busk. 



D. crassum, Cobbold, Simonds. 



D. buskii, Lankester, Moquin-Tandon. 



Dicrocoelium buskii, Weinland. 



This is a good species, and appropriately named ; for, although 

 Von Siebold (in Miiller's Archiv for 1836, p. 234, and in his Lehr- 

 buch, vol. i. p. 143) refers to a Distome infesting Hirundo urhica 

 under this title, he has given no description of the worm. Diesing 

 places Von Siebold' s D. crassum among his species inquirendce, and 

 it is very probably identical with the D. maculosum of Rudolphi. 

 No other instance has occurred since the original fourteen specimens 

 were discovered by Mr. Busk in the duodenum of a Lascar. From 

 a careful examination of three examples, severally presented by the 

 discoverer to the Museum of the Boyal College of Surgeons, the 

 Museum of the Middlesex Hospital Medical College, and to my pri- 

 vate collection J, I am satisfied that it is generically distinct from the 

 above ; but it is unnecessary to insist further on this distinction, as 



* Specimens of the Fasciola gigantea, thus prepared, were exhibited by me at 

 the Glasgow Meeting of the British Association in 1855, a description of them 

 being given in the ' Report,' Sect., p. 108 ; and -a more extended account of the 

 same appeared in ' Edin. New Phil. Journ.' for 1855, plate 7. 



t Since the above was written, I have received a communication from Professor 

 Leuckart, of Giessen, in which he mentions that he has at last succeeded in solving 

 many points respecting the phases of development through which this species 

 passes. A full account of these changes will doubtless appear in the second di- 

 vision of his valuable work (Die menschlichen Parasiten) now in course of pub- 

 lication. 



X I have forwarded this specimen to Prof. Leuckart in exchange for other rare 

 parasites.— T. S. C, Jan. 10, 1863. 



