Human Physiology. 



fish, instead of a flesh, diet it might be trebled. Then popu- 

 lation increases the fertility of a country, if its waste is put upon 

 the land, instead of being turned into the rivers and the sea. 

 The checks to population in a low state of development are 

 war, pestilence, and famine, and all the causes of infantile and 

 premature mortality; but in a higher development we shall 

 have the operation of two checks of a very different character. 

 With high mental and moral culture there will come the love of 

 chastity ; and we shall have the operation of the physiological 

 law that the higher the development of any race becomes, the 

 less is the number of individuals it produces. This law holds 

 throughout the vegetable and animal kingdom. The lowest 

 forms of life multiply with the greatest rapidity. In the higher 

 progeny grows more and more scanty. The educated and re- 

 fined classes, as a rule, have few children, and many are child- 

 less. Among the poor and ignorant children swarm. An 

 aristocracy is always dying out, and requires to be continually 

 strengthened by new blood. We have but to read the peerage 

 to see how many families have become extinct. The higher we 

 can raise the standard of intellectual and moral culture the less 

 will become the danger of over-population. Then, for cen- 

 turies to come, there will be the resource of emigration. In 

 this matter, as in so many others, we may be sure that ample 

 provision has been made for all needs. Nature is not an acci- 

 dent or a blunder. The destiny of man on the earth is guided 

 by Intelligence and governed by Law. We have simply to 

 conform to the order of Nature, and we need not fear for our 

 own fate or the fate of our posterity. 



The question respecting the amount of freedom that may be 

 safely given to young men and women in their intercourse with 

 each other, is one of the most important connected with the 

 regulation of sexual morality. The customs of different countries 

 and races differ very widely in this respect. In most oriental 

 countries, all women of the middle and upper classes are strictly 



