278 MODIFYING TEMPERATURE. 



class, man and the other mammalia; and, it 

 may be said, for the simple reason that these, 

 as regards the reproductive process, the em- 

 bryonic and foetal development, are in a great 

 measure independent of external temperature ; 

 the parents having within themselves the 

 power of preserving a constancy of temperature 

 by means of respiration that degree of tem- 

 perature most suitable to a healthy and vigo- 

 rous existence : the Greenland whale sporting 

 and breeding in the cold waters of the Arctic 

 Sea, as well as the Esquimaux wife and mother 

 breathing the air of an Arctic atmosphere, are 

 striking examples of such an independency. In 

 the instance of birds and the hatching of their 

 eggs, the temperature of which during the 

 brooding time is preserved pretty equably by 

 the transmitted warmth of the sitting mother, 

 the independency in question is displayed in 

 nearly an equal degree; but not so in the oviparous 

 animals, such as those of the reptile class, and 

 the class of fishes whose ova after* exclusion 

 are forsaken with few exceptions by the parents 

 and left to the mercy of the elements; and, 

 these indeed are merciful, and well supply the 

 absence of parental care ; showing again the 



