Periodic Activity. 117 



and disintegration, — grows and dies ; the body as 

 a whole wakes and sleeps, grows weary through 

 exercise and rests through repose. Waste and 

 repair follow each other from egg to adult; from 

 birth to death building up and tearing down con- 

 tinually succeed each other. 



Nowhere is this periodic activity and repose 

 more marked than in the reproductive life. 



A period of fertility and of great activity of the 

 whole organism is followed by a time of sterility 

 and rest. 



In all the higher life the reproductive activity 

 has its periods of quiescence when the phenomena 

 of sex attraction, of &<g^ and sperm maturing, are 

 for a time non-existent. During this period of 

 natural rest the organism has opportunity to make 

 good the waste of the preceding generative activity 

 and to prepare for similar future developments. 

 For after this season of rest there follows the sea- 

 son of reproductive activity, when again the egg- 

 cells mature in the female, the sperm-cells in the 

 male. As the wave of life rises to its crest in the 

 reproductive system, it produces a corresponding 

 exhilaration in other of the body tissues. As the 

 activity of the reproductive centres increases, the 

 whole being breaks into a spontaneous and sympa- 

 thetic anthem of quickening life. 



The living creature glows from excess of gener- 

 ative vitality, it bursts out in gay colors, in new 

 growths; all the differences between the two sexes 



