350 CHESTER A. STEWART 
The suprarenals in the test rats show a progressive increase in 
weight amounting to about 114 per cent at ten weeks, which 
usually is maintained, to a lesser degree, during the longer fasts, 
in the majority of cases. At ten weeks of age and also at subse- 
quent periods the suprarenals are heavier in the test females than 
in the test males of corresponding age and body weight, thus 
indicating the appearance of sexual differentiation in weight dur- 
ing underfeeding. 
There is an increase in the weight of the kidneys in the test rats 
at three, six, and ten weeks of age, but its variation from the nor- 
‘mal appears doubtful at later periods. 
The testes show a marked increase in weight in the test rats at 
three, six, and ten weeks, but later are variable, in some cases 
showing no change, and in other instances losing considerably in 
weight. 
There is an increase in the weight of the epididymides of 95 and 
14 per cent in the test rats at three and six weeks respectively. 
At ten weeks and later the epididymides apparently lose weight 
in the underfed rats. 
The ovaries show a marked increase in the test rats at three, 
six and ten weeks of age, but are variable later, in most instances 
showing a tendency to increase. 
There is an increase in the weight of the hypophysis in the test 
rats at three, six and ten weeks. Later the hypophysis is vari- 
able, showing a loss in the males and an increase in the females in 
most instances. In the very old test females the weight of the 
hypophysis is higher than in the corresponding males, indicating 
that sexual differentiation in the weight of the gland had occurred. 
There is apparently no definite change in the weight of the 
pineal body during either short or very long periods of fasting. 
In general, it therefore appears that in rats underfed from 
birth up to three, six and ten weeks, there is a marked increase in 
the weight of the spinal cord, eyeballs, liver, and stomach and 
intestines (empty). A less marked tendency to increase occurs 
in the brain (especially in the earliest period), heart (progressive 
increase), spleen (at six and ten weeks), intestinal contents (at 
six and ten weeks), suprarenals (progressive increase), kidneys, 
