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LVI. On the urinary Organs and Secretions of some of the Am- 
phibia. By Joun Davy, M.D. F.R.S. Communicated by 
the Society for the Improvement of Animal Chemistry .* 
Colombo, March 25, 1817. 
: Tue urinary organs of the amphibia have been imperfectly de- 
scribed by authors; but I am not aware that any account has 
hitherto been published of the urinary secretion of any of this 
class of animals. 
~ Since I have been in Ceylon, both subjects have excited my 
attention, and on both I have had favourable opportunities of 
gratifying my curiosity. It may not be uninteresting to the So- 
ciety to know the results of my observations. I shall briefly 
State them, confined as they are at present to a few animals of 
four natural families. 
1. Of the urinary Organs and Urine of Serpents. 
The kidneys of the different kinds of serpents I have examined, 
resemble each other generally; though in each kind there are 
minute and trifling differences. In every instance the kidneys 
are very large, nearly equal in size to the liver; they are long 
and narrow, and very lobulated ; like some of the mammalia with 
conglomerate kidneys, they are destitute of a pelvis ; each lo- 
bule sends a small duct to the ureter, which leaves the kidney 
in two branches. The ureters in general terminate in a sitgle 
papilla. The papilla is situated in thé cloaca between the mouths 
of the oviducts ; it is a little elevated above the surface, and its 
point is directed towards a receptacle into which the urine en- 
ters. The receptacle is a continuation of the intestine, yet it 
may be considered distinct both from the rectum and cloaca, with 
both of which it communicates only by means of sphincter ori- 
fices, This conformation of parts may be seen to advantage in 
large species of snakes. I first observed it in the rock-snake and 
the rat-snake, two species of coluber, frequently found from eight 
to ten feet long. 
The urinary ducts of serpents are frequently of an opaque white 
colour, from a white matter which they contain, which is visible 
through their transparent coats, and which may be expressed 
and collected from the papilla in small quantities for examina- 
tion. More or less of a similar white matter is almost constantly 
found in the receptacle ; generally it is found in soft lumps, rarely 
in hard masses. In the receptacle, I have always observed it 
pure and entirely free from fecal matter. This solid urine, for 
such it is in reality, gradually accumulates in the receptacle, till 
it forms the masses just described. It is a long time thus col- 
* Yrom the Philosophical Transactions for 1818, Part I. ; 
lecting, 
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