WEIGHTS OF UNDERFED YOUNG ALBINO RATS Beall 
When the weight of the eyeballs for the controls is compared 
with the weight for the test rats, it is evident that a marked in- 
crease has occurred in the latter. At ten weeks of age the in- 
crease in weight from an average of 0.093 gram in the controls 
to 0.155 gram in the test rats, equals an increase of more than 66 
per cent. At six and ten weeks of age the excess weight in favor 
of the test rats is less, being about 41 and 34 per cent respectively. 
- The increase at later periods, in some instances is even more 
striking, amounting to approximately 73 per cent (sexes combined) 
in the rats weighing nearly 50 grams after very long periods of 
fasting. 
My results, therefore, confirm Jackson’s (15 b) observation 
that the eyeballs show a marked growth capacity in young rats 
kept at maintenance for various periods. He suggests that the 
possibility of continued growth of the eyeballs is due largely to 
water absorption, the water content of the eyeballs being nor- 
mally very high (85.6 per cent at 20 days according to Lowrey’ 13). 
The eyeballs suffer practically no loss in weight during acute 
and chronic inanition in adult rats according to Jackson (15 a). 
A few observations were made concerning the time at which 
the eyelids opened in my albino rats. The data (table 3) in- 
dicate that the eyelids opened in my controls at an average age 
of fifteen days, whereas in the test rats the opening is apparently 
delayed until about the seventeenth day. The body weight of the 
controls when the eyelids opened averaged 16.5 grams as com- 
pared with 9.9 grams for the test rats. Therefore, although 
somewhat retarded in time, the eyelids nevertheless opened at a 
lighter body weight in the underfed individuals than in the con- 
trols. However, in the case of one litter (St 63) it was noted that 
the eyelids opened in two test rats weighing an average of 12.2 
-grams even at a younger age (15 days) than in the control. The 
exact age at which the eyes opened in the controls in this instance 
was not recorded except that it occurred after the fifteenth day 
at a body weight of more than 15.5 grams. * 
Bechterew (795) likewise found a delay in the opening of the 
eyelids in newborn dogs and cats subjected to acute inanition. 
Several investigators have noted the age at which the eyes 
