2 6o • . 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 immedately; in this state 

 they remained a week, and on being brought into the cabin 

 again, onty 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 

 onlv 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 b3 

 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 wissenschajtliche 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 

 different 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." 



