DE. T. S. COBBOLD ON THE PAEASITES OF ELEPHANTS. 241 



This species is the smallest of the Amphistomes hitherto obtained from Elephants. 

 Regard being had to the occurrence of large papilhe within 

 the cup of the caudal sucker, no one could mistake it for lg ' 



either of the two previously described species. LTowever, it 

 is just possible that the somewhat similar Amphistome from 

 the Tapir, described many years back by Diesing, may turn 

 out to be either the same or a mere variety. Dr. C. M. Die- 

 sing's Amphistomct asperum differs in form, the anterior part 

 of the body being much constricted, whilst the caudal sucker u ^° H! ( '^5 foam) /*" 

 is wider and terminal *. 



The enlarged view that I have given of this worm was taken from a perfectly 

 fresh specimen (PI. XXIV. fig. 11). In examples preserved in spirit the aperture 

 of the sucker gapes more widely, and consequently looks larger. In the fresh state 

 one not only sees the digestive organs through the transparent envelope, but also the 

 testes, part of the uterus, the branching ducts of the vitellaria, and even also their 

 terminal sacs. The latter are so small that I have not attempted to represent them ; 

 moreover, except as regards position, neither these nor the other internal organs offer 

 any striking peculiarities. In this species the vitellary glands are limited to the sides of 

 the body ; but in Hawkes's Amphistome the sacs and their ducts seem to underlie the 

 whole surface of the body. From hardened specimens I obtained fine transverse sections 

 in which the disposition of the muscle-fibres and general stroma of the body were well 

 displayed. 



As a believer in the common origin of all genera and species, of whatever zoological 

 type they may happen to be, I was not unprepared to find representative and parallel 

 forms of parasites in different animals. Thus it seems to me that the two Amphistomes 

 known to infest the Tapir represent two of the Amphistomes found in Elephants. On 

 the one hand my Amphistomct papillatum comes near to A. asperum, whilst on the other 

 my A. Rawkesii comes near to A. pyriforme. The Amphistomes of the American 

 Tapir were obtained by Natterer in Brazil in 1829, and were described by Diesing in the 

 Museum Annals already quoted. The Vienna helminthologist had not then lost his 

 eyesight ; and his elaborate memoir convincingly proves that modern anatomists, notwith- 

 standing our improved methods, have added little to our knowledge of the organization 

 of the trematode worms. 



The fungiform papillae within the sucker of Amphistomct papillatum forcibly call to 

 mind the more striking processes lining the ventral disk of the amphistomoid worm 

 which I have called Gastrodiscus Sonsiuonis. In this remarkable genus, established as 

 such by Lenckart, the gastric papilla; display each a central depression at the summit ; and 

 I have therefore spoken of them as suckerlets. On this account, also, I pointed to their 

 close affinity with those seen in the equally singular genera Notocotylus and Aspidocotylus, 

 as established by Diesing. The possession of the small suckers in question, shared as it 



* " Ncue Gattungen von Bmnemviirmen, ncbst cinem Nachtrage zur Monographic der Amphistomen." Annalen 

 des Wiener Museums, 1839, S. 236. 



33* 



