WEIGHTS OF UNDERFED YOUNG ALBINO RATS 339 
less marked. This is in agreement with my findings, excepting 
the youngest group. 
As compared with my controls, the weight of the empty ali- 
mentary canal is higher in the test rats at three, six and ten weeks 
of age than in the controls. At ten weeks of age the weight of the 
empty digestive canal apparently has nearly doubled in the 
underfed animals. 
At the later periods, however, the data indicate a reduction in 
weight of the empty alimentary canal, which is especially striking 
(34 per cent decrease) in the 4 males weighing about 75 grams at 
291 days of age. 
Jackson (15 b) likewise found the empty alimentary canal to 
increase in weight during the shorter maintenance periods, after 
which there was a decline in weight. 
During both acute and chronic inanition in adult rats there is 
a very marked decrease in the weight of the stomach and intes- 
tines, both with and without contents (Jackson ’15 a.). 
SUPRARENAL GLANDS 
The average weight of the suprarenals (table 2, sexes combined) 
(0.0027 g.) for my controls at one week agrees fairly with the nor- 
mal average (0.00226 g.) obtained by Jackson (13), but is far 
below the weight given in the Wistar tables for rats of: corre- 
sponding body length. Thus the weights for the suprarenals at 
one week derived from Hatai’s formula seem much too high, at 
least for normal rats from the Missouri and Minnesota colonies. 
For the controls at 13 and 14 days of age (table 2) the difference is 
less marked. 
As compared with my controls, the weight of the suprarenals 
(except in the four males at 291 days) is constantly higher in the 
test rats. The average increase in the weight of the suprarenals 
(sexes combined) in the test rats at three and six weeks of age 
amounts to more than 60 per cent (uncorrected for slight dif- 
ference in body weight). At ten weeks of age the difference has 
reached a maximum average of approximately 114 per cent. At 
later periods (except in the four males at 291 days, in which 
