274 DISEASE IN WILD MAMMALS AND BIRDS 
the vessels. This means further that only 14.3 per cent, of 
the chronic forms and 4 per cent, of the total seem closely 
related to disease of blood vessels. 
Nephritis has been found in 12.2 per cent, of our total 
autopsies. Mammals show an incidence of 20.6 per cent., 
birds 7.7 per cent. Only the orders upon which more than 
one hundred autopsies have been held are subjected to 
separate analysis. Some of the remaining orders give 
very high figures which may indicate great renal vulner- 
ability but it is deemed unfair to make statements upon 
them. Carnivorous mammals and birds lead their respec- 
tive classes, the succeeding order of renal vulnerability 
being marsupials, ungulates, rodents, Primates, Galli, 
Striges, anserine birds, parrots, and doves. The leaders 
of this list, Carnivora and Accipitres, occupy a definite 
position in the analysis of acute and chronic lesions. 
Their kidneys show the smallest percentages of acute 
lesions and the highest percentages of chronic lesions. 
This would seem to indicate a resistance to acute injuries 
but susceptibility to prolongated or repeated infections or 
intoxications. The relation of chronic infection of some 
sort to chronic renal disease is not as clear as the influence 
of acute infection to acute nephritis. Taking Carnivora 
for example ^\dth 34.2 per cent, of chronic nephritis we 
find 22.4 per cent, with evident chronic inflammation while 
in the 55 per cent, of acute forms 40 per cent, are of acute 
infectious origin — the relation is as 64 is to 74. 
While the relation of infection to nephritis is a con- 
sistent and perfectly acceptable one, the frequency of this 
disease in the carnivorous orders obliges one to think of 
high protein diet as a favoring factor. Renal disease is 
common enough in other orders, some strictly herbiv- 
orous, and it is fair only to emphasize which are the 
leaders in incidence. In so far as anatomy or habits are 
concerned no generalizations seem permissible. There is 
no relation of nephritis to the size of the kidney as given 
