and secretions of some of the amphibia . 30 7 
not surprising, their organic structure, and their habits and 
economy being so similar ; but that an analogy should exist 
between animals so very different in general appearance as 
birds and amphibia, is not a little singular, yet it is true : 
the urinary organs of one class, as well as the lungs, primae 
viae and genital organs, resemble those of the other, and both 
are peculiar in secreting uric acid ; those living entirely on. 
animal food secreting it pure 
MD0CCXVIIL 
Ss 
