192 RACE 



abnormal individuals whose peculiarities were 

 similar. This is the difficulty in accepting the 

 Mendelian hypothesis as an explanation of the 

 origin of fixed varieties or species. It may be 

 proved that certain peculiarities which arise as 

 " sports " are represented by certain elements in 

 the germ-cells that are not obliterated by inter- 

 breeding, although they may be concealed. A cross 

 that results from the interbreeding of such a 

 sport and a normal individual produces only a 

 certain proportion of reproductive-cells that 

 possess these new elements, so that if two such 

 crosses come together it would be necessary that 

 one of a particular number of sperm-cells from 

 the male should unite with one of a particular 

 number of germ-cells from the female, in order to 

 produce an individual in which the new character 

 would be fixed. This could only come about with 

 the closest in-and-in breeding, and from a 

 theoretical point of view the chances of the estab- 

 lishment of a new variety seem to be very remote. 

 But the fact remains that varieties have been estab- 

 lished : we owe to them the multiplicity of species 

 in the animal and vegetable kingdoms. They have 

 withstood the swamping effect of sexual interac- 

 tion. But it is clear, nevertheless, that marriage 

 has generally the effect of reducing eccentricity 

 to normality : we observe that relationship is 

 marked by resemblances of feature and character. 

 We also find this resemblance, although in a less 

 degree, within the circle of a nation, for, unless 

 interbreeding has been artificially checked, in the 

 course of few centuries the greater number of its 

 families have blood in common. 



It is difficult to realize how extensive are the 

 bonds of collateral relationship. Misled by genea- 

 logical tables we picture the continuance of a race 

 in the similitude of a tree. This serves its purpose 



