346 Annals Entomological Society of America  [Vol. VII, 
individual cells. The result is a formation of a parenchyma. 
which consists of single cells and of cell aggregates resembling a. 
morula. It is probable that a similar disintegration of parts 
takes place during hibernation and it is certain that it takes place 
during pupation. According to Sharp, when the larva of an 
insect has attained its full growth, many internal tissues disin- 
tegrate and rudimentary sex organs reabsorb the products of 
disintegration and with the other regenerative buds produce 
the perfect imago. On the contrary Jordan claims that the 
longer duration of the period of oviposition in the newt as com- 
pared with many other Amphibia may perhaps be correlated 
with the absence of the ‘‘fasting habit’’ (29). 
The foremost essential factors of hibernation judging from 
the above observations seem to be temperature and moisture 
conditions, over-feeding and maturation of the reproductive 
organs. It is often stated that the loss of water makes it pos- 
sible for the cell to withstand freezing temperature—for other- 
wise, as is claimed to be the case in plants (Vines 54) the ice 
crystals formed would rupture the cells. It is a known fact 
however that if cooled very slowly cells in which ice crystals. 
have been formed, will again become normal. Tower and 
Sanderson state that the loss in water of the protoplasm makes. 
it possible for this substance to stand greater variation in 
temperature for the concentration of salts makes the freezing 
point lower. But it is a known fact that the freezing point of 
sols is but sl ghtly lowered by an increase in the concentration of 
a salt dissolved. They also believe that it makes the protoplasm 
more able to withstand the high temperature but Loeb and 
Bachmetjew (3 and 4) have found that the point of coagula- 
tion of colloidal substances varies inversely with water content. 
This may account for the great killing of hibernating insects. 
which Wright (56) ascribes to a rather warm winter. 
Most animals that hibernate do so at a period just following 
great feeding and often at a time when their food is at its 
greatest abundance, as for example the cotton boll weevil, 
according to Sanderson (46). In some cases there is cytological 
evidence of overfeeding—for example, the overfed plasma cells. 
in the hedgehog and the vegetative staining quality of the cells. 
in the potato beetle and as I have found in the Codling moth 
larve. Overfeeding leads to increased number of molts or to 
hypermetamorphosis according to Sharp (51) who claims that 
