244 Cc. M. JACKSON 
is nearly the same as that found in the normal rat at fifty-six 
days. Since the body weight (77 to 79 grams) and suprarenal 
weight are also nearly the same as in the normal at fifty-six 
days, we may conclude that the normal rate of mitosis has been 
reéstablished in the suprarenal glands of stunted rats after two 
weeks of refeeding. As might be expected, no mitoses were 
found in the rat refed one year, which had reached maturity. 
Martinotti (’92) briefly states that in guinea-pigs starved 
three or four days an abnormal increase in the number of mitoses 
(20 to 25) in the suprarenal cortex was always noted. An in- 
crease in mitosis was also noted upon refeeding after several 
days of inanition. Unfortunately, further details are omitted, 
including the age and number of animals used. Bonnamour 
(05 b), on the contrary, found no mitoses in the suprarenal 
glands of the rat, guinea-pig, rabbit, and cat starved to death. 
Rondoni and Montagnani (’15) likewise observed no mitosis 
in the suprarenals in starved guinea-pigs. This would agree 
with my results on the albino rat. 
HISTOLOGICAL CHANGES IN THE SUPRARENAL GLAND 
In addition to the volumetric data previously given, the gen- 
eral changes in histological structure were observed. These 
include: 1) normal postnatal histogenesis in the albino rat; 2) 
changes in young rats stunted by underfeeding; 3) changes in 
rats refed after stunting by underfeeding, and 4) changes in 
adult rats after acute or chronic inanition. 
1. Normal postnatal histogenesis 
A brief account of the histology and histogenesis of the supra- 
renal will be given, with special emphasis upon the structural 
features of importance in connection with the changes pro- 
duced by inanition. 
New-born and first week. In sections fixed in Zenker’s 
fluid and stained with hematoxylin-eosin, the three cortical 
zones of the suprarenal in the new-born rat are fairly distinct. 
Under low magnification they appear as, 1) an outer zone 
