284 THE LIFE OF A BIRD. 



during incubation is not necessarily fatal to the 

 life of the chick. In fact, it would even appear 

 that such variations in the temperature to which 

 it is exposed are in reality favourable to the little 

 being. Possibly after a temporary relaxation of 

 vigour in the action of the organs of the little 

 being, they renew their functions with the greater 

 force and vivacity upon the return of the parent, 

 on the reapplication of her fostering warmth to the 

 surface of the egg. The application of too much 

 heat acts, however, as injuriously as too much 

 cold. Reaumur had a lively perception of the 

 fatal effects upon the life of the chick by excessive 

 heat ; and this is abundantly manifest in his co- 

 pious instructions to artificial incubators upon the 

 subject of thermometers. His own words on 

 this subject are so quaint that they deserve to 

 be quoted. 



" Although it is very certain that our country 

 pedlars will be very desirous to supply many 

 of the villages with* thermometers, yet a great 

 many years may pass, and all the villages that 

 might wish to have them may not be pro- 

 vided with them; especially those that are at 

 a great distance from large towns ; besides that, a 



