THE ANIMAL PARASITES 643 
like and most difficult to separate from the liver substance 
through which it ramifies. At maturity it dies and dis- 
integrates, leaving the ova distributed more or less 
in tracts through the liver substance, so that we are 
limited to a certain period wherein to obtain the mature 
form. The ova are not passed into the intestine, but re- 
main in situ, just as in the case of hydatid disease, and 
therefore diagnosis cannot be achieved by examination 
of feces. For the disease to be transmitted the host must 
die and its carcass be eaten or otherwise so disintegrated 
that the ova are distributed abroad. Another interest- 
ing observation is the long incubation period of the 
ova. Confirming Bancroft, we found that the ova only 
became larvated after they had lain in water at least 
three months. 
HOOKWOEMS. 
These important parasites have been taken from 
several foxes: Gray Fox (Canis cinero argenteus), Arc- 
tic Fox {Canis lagopus), Swift Fox {Canis velox), Red 
Fox {Canis vulpes pennsylvanicus) , a Gray Wolf {Canis 
mexicanus), divers members of the Felidae-Eyra {Felis 
eyra), Jaguarundi {Felis jaguarundi), American Wild 
Cat {Felis niffus). Spotted Wild Cat {Felis ruff us 
texensis), Ocelot {Felis pardalis), from two Giraffes 
{Giraffa camelopardalis, draff a capensis), a Malayan 
Tapir {Tapirus indicus), and a young California Hair 
Seal {Zalophus calif ornianus). It has been a most seri- 
ous infestment in American wild cats {Felis ruff us and 
Felis ruff us texensis) — animals which generally also har- 
bor other species of worms. In view of the petechial 
hemorrhages of the intestines and analogous circumstan- 
ces in dogs and human beings, it must be conceded that 
this worm is pathogenic. 
At tliis point it is fitting to note the infestment as it 
affects hair seals. The parasite concerned, Uncinaria 
lucasi, has long been a scourge among the fur seals 
