2 jo Human Physiology. 



the seminal fluid is thrown upon the mouth of the womb, which 

 probably opens by a similar action to receive it. The sperma- 

 tozoa which this fluid contains ascend by their own vital propel- 

 ling power, through the womb, and even penetrate through the 

 Fallopian tubes, against the ciliary action of the mucous mem- 

 branes, until they meet a germ or germs ready for impregnation. 



In vegetables and most insects this act of generation takes 

 place but once. As soon as the seed is formed the flower 

 perishes. The pea grows in its pod, which is its protecting 

 womb, hanging by a little stalk, which is its umbilical cord, 

 through which it draws its nourishment. So all seeds are pro- 

 duced and nourished. The male insect performs his function 

 in impregnating the one crop of germs produced by the female, 

 and then dies, in many cases in the very act. Among the 

 higher animals, where there are repeated births, through a series 

 of years, the sexual congress never takes place except when the 

 instinct of the female demands it for the "impregnation of 

 ripened germs. Life is never wasted in infertile and merely 

 sensual embraces. 



When germs are ripened but once a-year, the male organs 

 are quiescent, except at the period of use, and in some cases, 

 as in the various kinds of deer, they are shrunken and impotent 

 at all other times. Among elephants sexual union occurs, it is 

 said, only once in five years. The female carries her young 

 two years, and nurses them two years more; and among 

 animals living in a state of nature there is never sexual union 

 during pregnancy or nursing, nor, in fact, at any time except 

 when naturally required for the purpose of generation. Every 

 male animal, however he may express his readiness or his de- 

 sire to perform his part of the reproductive act, awaits the call 

 of the female, and as soon as her requirement is satisfied, that 

 is, as soon as conception has taken place, she refuses further 

 connection, which, so far as I know, among animals living in 

 natural conditions is never forced upon an unwilling female. 



