266 DISEASE IN WILD MAMMALS AND BIRDS 
tations of such work. Grossly diseased organs are 
naturally excluded. More avian weights are not available 
because of the difficulty of removing the organ from its 
bed, in a manner assuring us of completeness. I am 
inclined to \dew our mammalian records as fairly repre- 
sentative. Figures to be found in text-books of human 
and veterinary anatomy correspond to those given by the 
authors just quoted and in our own list. The values for 
rodents, hyraces, edentates and monotremes may be modi- 
fied by more figures. 
There is however one point which does not appear in 
the list. Small animals have relatively larger kidneys 
than large animals. This is perhaps most strikingly 
illustrated among the ungulates which have the lowest 
value quoted. A small deer had a kidney-to-body index 
of 5.9 grams per kilo while a camel had only 2.8. Judging 
by the work of Magnan the avian kidney should be larger 
than the mammalian, a conclusion with which I am 
inclined to coincide, even though the weights cited do not 
bear this out. 
In so far as the function and chemistry of the kidney 
and its excretion are concerned this study can supply 
little. The general metabolism is known for most 
animals, it being dependent upon diet and gastrointestinal 
discharge of excrement. What lessons can be learned 
will be discussed by Dr. Corson- White in the section on 
diet. Our observations upon the ability of the kidney to 
excrete normal urine are limited to the examination of 
vesical contents at death or of the occasional specimen 
obtained in cages in the quarantine room. Renal disease 
was formerly considered of little or no importance in 
veterinary medicine or at least was studied only as a 
specific separate and occasional occurrence. Kitt(6) 
systematized the knowledge of the subject at the time he 
wrote but it remained for Hutyra and Marek in their 
text-book to emphasize its general importance and to 
(6) Monatsh., 1893. 
