Zoe Cc. M. JACKSON 
4. In adult rats during acute or chronic inanition 
In adult rats subjected to acute inanition seven to nine days, 
with loss of about one-third in body weight, the relative volumes 
of cortex and medulla remain nearly normal (table 2 B), indicat- 
ing that the loss (if any) has been nearly proportionately distrib- 
uted. In rats after chronic inanition due to gradual decrease 
of food for five weeks, with loss of about 36 per cent in body 
weight, the medulla averages a little higher. This may indicate 
a relatively greater loss of the cortex, but the difference is small 
and of doubtful significance. 
VOLUMES OF SUPRARENAL PARENCHYMA AND STROMA 
The averages (and ranges) of the percentages by volume formed 
by the stroma, including the vessels, are summarized by groups 
in table 3. The variations are due chiefly to the differences in 
blood content. On account of the great variability shown, no 
conclusions can be drawn with certainty. Neither the groups 
nor the individual data reveal any marked change in the normal 
vascularity of the gland from new-born to adult. There is in 
general, however, an increased vascularity evident upon passing 
from the outer zone of the cortex toward the medulla, with the 
exception of a decrease in the outer part of the middle zone. 
More than one-fourth of the medulla by volume is composed of 
stroma and included vessels. 
In the young rats held at maintenance the vascular stroma ap- 
pears moderately decreased in relative volume in the outer and 
middle zones and greatly increased in the inner zone, with but 
little change in the medulla. The hyperemia of the inner zone 
is usually strikingly apparent in the sections under the micro- 
scope (low power). 
In the rats refed one or two weeks after maintenance experi- 
ments, there appears in general a reduction in the relative volume 
of the vascular stroma in the most hyperemic regions—medulla 
and inner cortical zones—and an increase in the vascular stroma 
of the middle zone. The outer cortical zone, however, appears 
even more anemic than before. 
