242 
ment on this matter until further evidence is 
available. 
McKeever (1959) reviewed the effects of 
reproductive hormones on adrenal size in mam- 
mals, stating that in general androgens decrease, 
and estrogens increase, thickness of the adrenal 
cortex, and that this results in changes in adre- 
nal weight. These effects are suggested by data 
on the mongoose because of the gradual reduc- 
tion of relative adrenal size in the maturing 
male and its sudden enlargement once the 
female is adult. 
Histological study (McKeever and Tomich, 
1963) confirms the above observations and 
reveals an inner zona fasciculata in adrenals of 
adult female Herpestes auropunctatus which ac- 
counts in part for the large cortical width in 
that class. This subzone reaches its greatest 
development during lactation, when cortical 
width and adrenal weight are at a maximum. 
The implications of adrenal size patterns as 
they vary in the several orders of mammals are 
not completely elucidated by available data. At 
least some lagomorphs are unlike the carnivores; 
in both Oryctolagus and Sylvilagus adrenals of 
all age groups are larger in males than in fe- 
males, about 40% heavier when considering all 
PACIFIC SCIENCE, Vol. XIX, April 1965 
age classes together ( Wodzicki and Roberts, 
I960). Two species of ground squirrels ( Citel - 
lus), whose adrenal weights are known, depart 
from the usual pattern in rodents and also have 
significantly larger adrenals in males than in 
females (Tomich, 1962), but in a third species 
(McKeever, 1963) the reverse is true. There is 
little evidence from behavioral observation to 
show why these conditions may vary so widely 
among closely related groups or be so similar 
in distantly related groups of mammals. It 
seems probable, nevertheless, that carnivores in 
general are conservative in adrenal responses 
measureable by the condition of these organs, 
when compared with the better known lago- 
morphs or rodents. 
ACKNOWLEDGMENTS 
This research was supported by the State of 
Hawaii Department of Health and by National 
Institutes of Health Grant E-2886, Charles M. 
Wheeler, Principal Investigator. Oliver P. Pear- 
son and Sturgis McKeever read the manuscript 
and offered many useful suggestions for its im- 
provement. Larry A. Nelson and Albert L. 
Tester gave their time and advice freely in 
the more elaborate statistical analyses. 
TABLE 2 
Adrenal Size (in mg/ 100 g body wt) in the Mongoose by Age and Sex 
During a Three -Year Period 
CLASS 
YEAR 
NUMBER 
RANGE 
MEAN 
SE 
Young males 
1st 
34 
24 . 2 - 58.1 
35.8 
±- 1.44 
2nd 
23 
21 . 9 - 53.8 
35.7 
1.81 
3rd 
25 
20 . 6 - 46.3 
32.0 
± 1.53 
all 
82 
20 . 6 - 58.1 
34.6 
±: 0.92 
Young females 
1st 
38 
26 . 1 - 58.7 
40.4 
± 1.41 
2nd 
39 
24 . 4 - 56.6 
39.1 
± 1.37 
3rd 
56 
20 . 8 - 60.2 
36.3 
± 1.24 
all 
133 
20 . 8 - 60.2 
38.3 
± 0.78 
Adult males 
1st 
71 
10 . 4 - 72.4 
27.4 
± 0.92 
2nd 
72 
11 . 9 - 45.0 
26.3 
± 0.89 
3rd 
72 
12 . 8 - 62.3 
25.6 
ft 0.91 
all 
215 
10 . 4 - 72.4 
26.4 
it 0.52 
Adult females 
1st 
152 
26 . 2 - 87.3 
52.0 
± 1.07 
2nd 
84 
24 . 6 - 97.5 
50.5 
± 1.68 
3rd 
118 
26.0-99.6 
49.7 
± 1.31 
all 
354 
24 . 6 - 99.6 
50.9 
± 0.73 
