36 IOWA ACADEMY OP SCIENCES. 



First. — The small, active cell imparts its kinetic energy to 

 the large, passive cell, and that energy expresses itself in cell 

 division. 



Second. — The large, passive, anabolic cell imparts to the 

 daughter cells its anabolic propensities, which express them- 

 selves m growth. 



By the growth and division of cells every organism, from 

 the hydroid to man himself, attains its perfection. 



It will be seen from what has been said that there is no 

 fundamental difference between the reproductive processes in 

 the Protozoa and Metazoa. Ail of the complicated machinery 

 associated with sex in the higher forms are merely accessory to 

 the fundamental fact of the meeting of two cells, an inter- 

 mingling of protoplasm and a subseqiient cell division, all of 

 which phenomena are essentially present in the conjugation 

 and fusion of the Paramecium for instance. 



As to the significance of sex, it is not sufficient to say that it 

 serves to perpetuate the species. It does much more. It 

 serves to improve species in that the commingling of the char- 

 acteristics of two parents furnishes the main potentiality for 

 individual variation among the offspring. Indeed, Weismann 

 stoutly maintains that we have here the only cause for indi- 

 vidual variation upon which natural selection can act, and he 

 believes that evolution would be impossible among sexless 

 animals. However this may be, it is clearly true that progress 

 is much more rapid and certain by virtue of the fact that most 

 individuals animals have a> father and a mother. 



It would be impossible in the limits of this paper to discuss 

 the tremendous ethical, social and moral significance of sex. It 

 must suffice to suggest that altruism had its birth in the world 

 when brutes first cared for and protected their helpless young, 

 and that through the social relations of parent and child, hus- 

 band and wife, all that is purest and best in human affairs found 

 its inception and its impetus. 



