Ii4 Life and Love. 



ing a nest for its eggs; while certain cells in the 

 lining membrane of the crop in some birds disinte- 

 grate and form with the food a milky substance 

 which is regurgitated and fed to the young. 



The emotional power of the creature is also 

 greatly affected by the physical exhilaration of the 

 love season. The bird fairly overflows with joy 

 and life, and this happiness it expresses by bursts 

 of song. It sings from very love of love. The 

 more active male here too shows his excess of 

 vitality, for his song far surpasses that of his part- 

 ner, though she cannot refrain from also singing 

 her song of jubilee. Perhaps she best shows her 

 appreciation by yielding her heart to that gay little 

 cavalier who renders the finest music, thus insuring 

 to the world sweet sound as well as bright color. 



Not only in song and happiness, however, is the 

 superactivity of the love season expressed. Some- 

 times the exact opposite is the case, and there 

 arises a vehement desire to fight and quarrel. 



Even birds sometimes indulge in very unseemly 

 behavior towards each other at this time. 



Among mammals a fierce disposition is not un- 

 common in the adult male. And among nearl)' 

 all male animals the cruel and selfish emotion of 

 jealousy is easily aroused during the breeding 

 season. 



This darker side is only one out of many ways 

 in which the activity of the love season expresses 

 itself, and in the history of the race this individual 



