CH. IX] OF DOMESTIC ANIMALS 315 



belonging to the genera Tcenia, Drepanidotcenia, Dicrano- 

 tcenia, Bothriotcenia, Echinocotyle and Davainea are known 

 to infect poultry, including geese, pigeons and pheasants 

 as well as ducks and fowls in this term. The intermediate 

 hosts are not known in every instance, but where they have 

 been determined they are always the natural food of the 

 final host. Thus the tapeworms of the duck and goose 

 pass the bladder- worm stage in small fresh -water crus- 

 taceans such as GammaruSy Cyclops, and Cypris. Those 

 of the fowl, pheasant and pigeon in earthworms (Allo- 

 lobophora fcetida), slugs (Limax), house-flies and other 

 insects the pupae of ants being suspected of harbouring 

 one species (Davainea friedbergeri) that becomes mature 

 in the pheasant. 



Mice and rats are liable to be infected by a small tape- 

 worm (Hymenolepis diminuta), whose bladder-worm stage 

 is found in various insects, but especially in the meal 

 moth, Asopia (Pyralis) farinalis. The habits of this 

 moth render it peculiarly likely to come within reach 

 of the above rodents. 



It is somewhat surprising to find that purely herbi- 

 vorous animals are not exempt from this class of entozoon. 

 About a dozen different species of the genus Moniezia 

 have been described from the intestines of sheep, goats, 

 oxen and other ruminants. Others of like habits belong 

 to the genera Thysanosoma and Stilesia. Similarly from 

 the intestines of rabbits, hares, horses and asses 

 numerous tapeworms, some small, others attaining a 

 length of two or three feet have been taken. Those of 

 the horse are of the genus Anoplocephala, of the rabbit 



