Nutrition and Reproduction. 1 5 1 



sumption of abundant food on the part of ,the 

 mother will result in the production of female 

 offspring. This is doubtless true in the simple, 

 lower forms of life. In the higher forms it may 

 not be true. The various tissues appropriating 

 food with unequal readiness, one kind may thrive 

 and the creature present a well-fed appearance 

 from an accumulation of fatty tissue, while the 

 reproductive tissues have more feebly appropri- 

 ated nutriment, and produced as a result males. 



In the higher life the production of male or 

 female seems to depend upon the power of the 

 generative centre to appropriate nourishment. 



It is probable that abundant nutriment, warmth, 

 and composure tend to the production of females, 

 even in the higher forms. 



Since reproduction and nutrition are so inti- 

 mately connected, it is not surprising to find that 

 the age at which the reproductive system matures 

 is a gauge of the length of life. 



In the higher animals, the length of life seems 

 to be four to five times that of the period of 

 maturity; thus, the dog, which develops at two 

 years of age, has a life lease of about ten years ; 

 the cow, which becomes sexually mature at two or 

 three years of age, lives from twelve to fifteen, and 

 the elephant, which is not sexually mature until 

 about twenty, lives a corresponding length of time. 



It is also worthy of note that in early youth the 

 weaker, less well-nourished male succumbs sooner 



