Human Physiology. 251 



In the higher orders of animals, fishes, reptiles, birds, and 

 mammals, the production of germs goes on year after year in 

 varying periods. The guinea pig begins to breed at two months 

 old, and the higher the type, the later is the period of germ 

 formation, until in man the period of puberty, or the be- 

 ginning of the generative function, is at about fifteen years, 

 varying from twelve to eighteen; but the natural powers are 

 scarcely at their full strength and fitness until some years 

 later. 



The power of reproduction as to numbers seems to be in the 

 inverse ratio as to development. The lowest forms of life 

 multiply with amazing rapidity; some insects produce myriads,' 

 fishes spawn eggs by millions, hens lay an egg a-day for months 

 together, rabbits, cats, dogs breed every few months, and have 

 at each birth a numerous progeny, while the higher orders of 

 mammalia produce their young but once a-year, and have but 

 one, or, in rare cases, two at a birth. When the human germ 

 has been slowly formed in the ovary, and perfected up to the 

 period when it bursts forth in its first birth, fit for impregnation, 

 it is nine months in arriving at the development which fits it for 

 birth and independent existence. For twelve months more it 

 draws its supply of nutriment from the mother, and two years 

 may be considered the normal interval from birth to birth. It 

 should never be less with a proper regard to the health of the 

 mother, and the proper development of her children ; and the 

 practice of shortening this period by hiring wet nurses is a 

 violation of nature which is avenged on parents and their off- 

 spring. The mother is exhausted by too frequent child bear- 

 ing, and children are deprived of the love, the magnetism, the 

 life of the mother, which comes to them from her blood trans- 

 formed into the most delicious food for them, and the nervous 

 and spiritual food which no money can buy, and no one but 

 the mother can give. 



The human germ cell, or egg, is formed from the blood in a 



