344 Annals Entomological Society of America  [Vol. VII, 
water—the cytoplasm becomes more watery, vacuoles appear, 
the cells become larger and more turgid and the chromatic 
elements stain deeply and increase in size, thus presenting all 
the signs of intense activity. The preparation in the potato 
beetle for estivation is similar to that of hibernation—the ani- 
mal remaining underground until first rains. Tower states. 
here that the reduction of water gives an increased capability 
of meeting higher temperatures. 
Hibernation usually follows a period of great feeding— 
whether this is what makes hibernation possible or whether it is. 
the controlling factor of hibernation or not is unknown. In the 
marmot, there is a definite storage gland called the hibernation 
gland and Cleghorn includes in his definition of hibernation, the 
formation of reserve fat to be used during that period. In the 
potato beetle, the great period of feeding takes place before 
hibernation and estivation (a little less in the latter) this 
oversupply of food is stored up in the fat body and is used to a 
certain extent during hibernation for there is a decrease in 
weight of the insect during that period. The spermophile and 
the marmot according to Cleghorn go into hibernation imme- 
diately after having laid up the last layer of fat. This occurs. 
at a period when their food is most plentiful. The frog accord- 
ing to Holmes (23) goes into hibernation immediately after a 
period of great feeding. There is. some evidence that over- 
feeding takes place just before hibernation, in the Codling moth 
for example: Hammar (20) has found that the feeding period 
of the larve of the first brood (transforming directly into pupz) 
lasted 24.7 days while that of the first brood which hibernated 
lasted 28.9 days and the whole second brood (hibernating) 
34.2 days. Inthe next year (1911) he found that the first brood 
which was to transform had a feeding period of 21.2 days. 
while that part of the first brood that was to over-winter as. 
larve fed for 28.2 days. Jones and Davidson (28) find that the 
second brood feeds twenty days longer than the first and at a 
higher mean temperature. Jenne (26) finds in like manner 
that the over-wintering brood of larve fed a longer time (.8 of a 
day) than the transforming brood. 
Morgulis (38) has found that during hibernation, the 
nucleus is nourished by the cell—during starvation on the con- 
trary, the nucleus at first loses volume rapidly though it re- 
mains more or less unaffected after it has attained a certain 
