THE GENESIS OF SEX. 177 



the altruistic — the one concerned only about the well-being of self, the 

 other about the well-being of the race. These correspond each to 

 each. Traced to its deepest physiological roots, the one in its last 

 analysis is connected with the nutritive functions and the appetite for 

 food, the other with the reproductive functions and the sexual appetite. 



It seems to me not inappropriate to draw passing attention to the 

 fact that that form of woman's rights which would assimilate as much 

 as possible the two sexes is certainly in direct conflict with the law of 

 evolution which we have been tracing. If founded in nature at all, 

 we must seek for its justification in a higher law than that of animal 

 evolution. 



7. Crossing of Varieties, — Are there still further differentiations 

 and still better results possible ? Yes ; by judicious crossing of varie- 

 ties. Groups of individuals of both sexes, under the influence of dif- 

 fering environment, become different. This difference may be slight 

 (slight varieties), or decided (strong varieties), or still more decided 

 (races), or may become in time so great as to constitute distinct 

 species. Now, it has been found that the indefinite interbreeding of 

 individuals subject to identical conditions (close-breeding) produces 

 weakness and degeneracy ; and, on the contrary, the judicious cross- 

 ing of slight varieties produces improved results. The reason is ap- 

 parently this : Among all the qualities, good and bad, strong and 

 weak, inherited from both sides by the offspring, there is a kind of 

 struggle for life, and a survival of the best and the strongest qualities. 

 It is probable that this improvement is more decided in the psychical 

 than in the physical nature, and therefore is more conspicuous in man 

 than in animals. Too close breeding — i. e., the interbreeding in iso- 

 lated communities of individuals subject to identical conditions, and 

 therefore with identical customs, habits, feelings, thoughts — tends to 

 deteriorate the mind and character, even when the physique is unim- 

 paired ; tends to petrify the communal character and destroy that plas- 

 ticity on which all progress depends. 



Now, it is quite certain that toithin certain limits the improved 

 results of crossing increase with the diversity of the crossing varieties. 

 But mark, only within certain limits, beyond which they again decrease 

 until deterioration is reached ; and the deterioration increasing with 

 the increasing divergence, when the crossing varieties reach a diver- 

 gence represented by the term species, Nature practically forbids the 

 ban. Thus, when species cross, there is either {a) no fertilization, and 

 therefore no offspring ; or {h), the offspring is an infertile hybrid, and 

 therefore perishes in the next generation ; or (c), if the offspring be 

 fertile, the progeny is feeble, and perishes in the struggle for life in a 

 few generations, or {d) is absorbed by crossing with the stronger 

 parent species. If this were not so, species, in many cases at least, 

 could not exist. Many species of oak or of pine grow in the same 

 grove ; the air is full of the pollen of many species ; the conditions 

 VOL. XVI. — 12 



