Periodic Activity. 123 



the care of the young is rare ; in the bird it is 

 almost universal, and what is unusual in all but the 

 highest form of earth life, the male too is imbued 

 with a strong parental instinct. 



Parental love is one of the blossoms of the plant 

 of which sex-love is the root; less selfish, more 

 altruistic, it is, like the flower, a finer development 

 of the parent stem. 



