26 o 
The Ohio Naturalist. 
[Vol. VIII, No. 4, 
A quotation from an account of Sir John Ross’s second arctic 
voyage recording experiments carried out with a moth, Laria 
rossi, has a bearing here: 
“About thirty of the caterpillars were put into a box in the 
middle of September, and after being exposed to the severe win¬ 
ter temperature of the next three months, they were brought 
into a warm cabin, where, in less than two hours, every one of 
them returned to life, and continued for a whole day walking 
about. They were again exposed to the air at a temperature of 
about -40, and became hard frozen immedatelv; in this state 
they remained a week, and on being brought into the cabin 
again, only 23 came to life. At the end of four hours these were 
put out once more, and hard frozen again; after another week 
they were brought in, when only 11 were restored to life. A 
fourth time they were exposed to the winter temperature, and 
only two returned to life on being brought into the cabin again. 
These two survived the winter and in May an imperfect moth 
was produced from one, and six parasitic flies from the other.” 
From what has been said it is evident that some larvae will 
not be killed by very low temperatures, while others may be 
killed by a frost that is sufficient to kill tender foliage, also that 
all the difference is not in the species, for some specimens may 
be killed while others of the same species are not killed by the 
same exposure. 
P. Bachmetjew of Bulgaria, has published an extended paper 
in Zeitschrift fur wissenschaftliche Zoologie for 1899, from which 
the following conclusions are extracted: 
“The thawing out of insects after their body fluids have been 
frozen has no noticeable influence upon their return to life, but 
only upon the intensity of their vitality.” 
‘The critical point is not the same in different species, nor in 
difl'erent individuals of the same species.” 
“The longer an insect has gone without food, the lower is the 
normal freezing point of its body fluids.” 
“Repeated freezing lowers the critical point and also the 
normal freezing point of the body fluids.” 
