444 DISEASE IN WILD MAMMALS AND BIRDS 
feeding the amount needed for energy is burned, the 
remainder is stored in the liver up to its capacity, then 
in the muscles and other cells, after which fat is formed 
and all further excess is eliminated by the kidney. Over- 
feeding causes an immediate overloading of the oxidative 
mechanism with symptoms of gastric disorder, achylia, 
and at times acid fermentation with irritation of the 
stomach walls and the development of bacteria in the 
organ. This is frequently followed by glycosuria, several 
types of which are described: (1) associated with an 
increased concentration of glucose following excessive 
ingestion exceeding the normal glycogenic function of the 
liver, a form common among the Herbivora, (2) that due 
to a reduction of the glycogenic function of the liver, (3) 
that associated with disease of the ductless glands in 
which the resulting glycosuria probably depends upon the 
influence of these glands upon the pancreas, (4) that 
dependent upon the defect of glycolysis or to an over- 
stocked liver seen in gout, obesity or hypertrophic cirrho- 
sis, and (5) renal glycosuria due to a lowering of the 
renal threshold and usually associated with gout, arterio- 
sclerosis or chronic nephritis ; this last is best explained 
on the ground of increased renal permeability. Normally 
when the blood sugar concentration rises above a certain 
level the elimination via the kidney begins and continues 
until the blood has again reached its normal concentration. 
The relation of the kidney to glucose concentration is 
not constant and variation is always toward the side of 
lesser elimination while the kidneys become accustomed 
to the higher level. 
Diabetes, a disease of the islands of Langerhans in 
the pancreas, is essentially a disturbance of sugar metab- 
olism always associated with an exaggerated and defec- 
tive fat and protein combustion. It is not only that the 
diabetic has lost the faculty of combustion but these 
abnormalities all establish states of intoxication to which 
the diabetic must sooner or later succumb. Among lower 
