THE HORMONES IN HUMAN REPRODUCTION 



animals, and in the higher orders seems a task for the female 

 alone. There is indeed one species in which the male animal 

 plays no other part at all in life than this — the marine worm 

 Bonellia, famous in biological lore, in which the male is noth- 

 ing but a very small parasite on the gills of the female. She 

 carries this petty creature about with her for the sole purpose 

 of getting the eggs fertilized. Yet he cannot wholly be dis- 

 pensed with, however brief his moment. In human history a 

 not dissimilar career has been that of certain prince consorts 

 of masterful queens. 



Such is not altogether the case in mammals. The very fact 

 that gestation is a heavy burden, putting the female at a 

 disadvantage in the struggle of life, while she is carrying her 

 young and afterward mothering them, gives the male parent 

 another task — that of protector and leader of the family. 

 This finds biological expression in the fact that in almost all 

 mammals the male is larger, stronger, and fiercer than the 

 female (Rudyard Kipling to the contrary notwithstanding). 

 In the human race the mother's burden is heaviest of all, and 

 by that very fact the father becomes again biologically useful 

 to his offspring during the long period of gestation and 

 infancy, as guardian and provider of food and shelter. 



Meaning of Sex for Human Beings 



The gist of our preface to human reproduction is that our 

 own species and most of the others, high and low, reproduce 

 themselves by the production and union of eggs and sperm 

 cells. To get this essentially simple task done in the highest 

 animals requires the functioning of an elaborate set of 

 organs. In order to tell the whole story of reproduction in 

 man and the higher animals we shall have to discuss : 



The anatomy of the ovary and testis and the formation 

 of eggs and sperm cells, 



{ se } 



