SUPRARENAL GLAND—EFFECTS OF INANITION 229 
relatively large (as in the female St 5.1 at 56 days). In very large 
glands, on the contrary, the medulla is usually relatively small. 
This suggests that the variability in the size of the suprarenal may 
be due mostly to variability in the volume of the cortex. 
On account of the known sexual difference in the weight of the 
suprarenals (which become relatively heavier in the female from 
the age of about six weeks),? the question naturally arises concern- 
ing the relative sizes of cortex and medulla in the two sexes. As 
shown by table 2 A, however, the present data grouped by sexes 
reveal no constant or important differences in this respect. A 
study of the individual data likewise reveals no constant sexual 
differences in the absolute or relative sizes of the suprarenal cor- 
tex and medulla. It is possible that a larger number of obser- 
vations would reveal differences obscured by large individual 
variations (or experimental error) in the present small series of 
data. Provisionally, however, on the basis of the present data, I 
would conclude that the relatively larger suprarenal gland in the 
female is due to an increase in both cortex and medulla, with no 
important change in their relative sizes as compared with those 
of the smaller gland in the male. Thus the conditions in the 
suprarenal would appear to be different from those in the hypo- 
physis, where the relatively larger gland in the female is appar- 
ently due to a larger pars anterior (Jackson, 717). 
In one female (J 1.7) which had just given birth to a litter 
the suprarenal glands were not hypertrophied (table 1), being on 
the contrary below the normal weight for corresponding body 
weight or length. The volumetric relations of cortex and medulla 
appear normal, the latter forming 7.2 per cent of the total vol- 
2 Elliott and Tuckett (’06) noted in several cases that in the rat, cat, guinea- 
pig, and rabbit of reproductive age the suprarenal glands were larger in the 
female. They considered this a temporary hypertrophy, however, concluding 
that ‘“Gestation accelerates the growth of the gland, so that for a time that of 
the female outstrips the male. In such increase the cortex is concerned, but 
there is undoubtedly growth of the medulla also. Our analyses are too few to 
trace the changes satisfactorily.’? That the larger suprarenal in the female rat 
is a regular sexual characteristic, independent of gestation, was first established 
by Hatai (13) and Jackson (13). 
