COLD HARDINESS 227 



for studying the undercooling and rebound points and for main- 

 taining a continuous accurate record of body-surface temperatures. 

 Many important aspects of the subject are dealt with, and among 

 them the effect of moisture in contact with the body-surface may 

 be specially mentioned. This is usually in the form of ice, and in 

 many insects it is found to result either in the reduction or com- 

 plete elimination of the capacity for undercooling. In some other 

 insects it seems that no effect in this connection results from a 

 relatively heavy coating of ice or water. 



