34 DISEASE IN WILD MAMMALS AND BIRDS 
tangled thread and tape worms frequently found in birds. 
The effect of swelling by the mucous membrane under the 
influence of worms is illustrated by the infestation of the 
proventricle in parrots. Here spiroptera penetrate into 
and under the glandular layer which swells and pours out 
mucus, the total mass of nematodes, mucus and tissue 
obstructing the passage. 
Very many animals show parasitic infestation at post- 
mortem, but the percentage in which they can be said to 
be principal causes of death is quite small, while that in 
which they play a role as activa,tor of the terminal condi- 
tion is also small but indeterminate. The latter group 
comprise, together with the anemias mentioned above, 
certain forms of pneumonia, of hepatic and vascular 
lesions. Inflammations of the lungs from ascaris and 
paragonimus are fairly well known ; fortunately we have 
been troubled less with this than have most gardens, pos- 
sibly because we do not have such large herds of herbivora 
susceptible to it. Hepatic diseases from flukes, from coc- 
cidia and from amoebae we have always with us in small 
numbers, but they are unimportant excepting enterohep- 
atitis, a condition which appears in nearly all orders. 
This last disease, be it purely amoebic as in dysentery of 
man and monkeys, or like blackhead of turkeys and chick- 
ens or in the forms of quail disease, arrests the attention 
at once and evokes a desire to explain the association of 
large intestines and liver. Parasitic vascular lesions are 
relatively unimportant. 
Taking parasitic infestations by and large, there are 
close similarities throughout the entire animal kingdom, 
and the effects produced by a given genus will be repeated 
almost exactly in several others. The pathological pic- 
tures of anemia, of hepatic degeneration, of cystic 
degeneration, of colonic ulceration or of fibroses are simi- 
lar in different hosts, only slight variations in the type of 
inflaromation being noted, for instance in reptiles and 
birds as against the mammals. We have made rather close 
