77ie Laws of Heredity. 149 



It is easy to account for the disagreement between logic and 

 experience. No law of nature is unconditional. They all require 

 certain determinate conditions for their realization ; and where 

 these fail, the action of the law rests suspended, or without efficacy. 

 But nowhere are the requisite conditions more numerous or more 

 difficult to fulfil than in the phenomena of generation. For in 

 order to produce in the infant this perfect equilibrium of paternal 

 and maternal qualities, there must evidently be perfect equality of 

 action on the part of both parents ; for it will be admitted that in 

 all races, and in all species, the general or partial preponderance in 

 the act of reproduction appertains to that one of the parents in 

 whom the general or partial force of constitution is the greater. 

 A great number of facts, collected by a crowd of writers, show 

 that this rule applies both to the vegetal and the animal world. 

 This preponderance of one of the procreative individuals is very 

 notable in crosses between distinct races or species. It is true 

 that in this case there is a struggle not only between the sexes, 

 but between distinct specific forces. These crosses, however, only 

 exhibit to us, more or less magnified, what takes place in ordinary 

 cases. According to Rursh, marriages between Danes and East 

 Indian women produce children with the physique and the vigour 

 of the European type, while nothing of this kind occurs when 

 these same women marry other Europeans. The intermarriage of 

 Causasians and Mongolians produces, according to Klaproth, 

 half-breeds in whom the Mongolian type is always predominant, 

 whatever may be the sex of the half-breed. From Levaillant's 

 observations (Voyage en Cafrerie) on the half-bred children of 

 Europeans and Hottentots, we gather that in them the moral 

 nature is always determined by the race of the father. ' When- 

 ever it happens, which is but rarely, that a white woman has 

 intercourse with a Hottentot, the child has always the good-nature, 

 and the gentle and kindly inclinations, of the father. But the 

 children of white men and Hottentot women, on the other hand, 

 have in themselves the germs of all vices and unruly passions.' 

 Cross breeding in the animal races exhibits also the unquestionable 

 preponderance of one of the parents. 



This being admitted, it may be readily shown that among the 

 higher animals the complete conditions necessary for the realiza- 

 tion of the ideal law can nowhere be found. 



