146 BLASTOGENIC VARIATIONS. 



originally, only that they seldom have an opportunity of 

 showing themselves. They are covered up by the more 

 recently acquired characters, and it is only under ex- 

 ceptional circumstances that they are able to reveal 

 themselves. When, for instance, two distinct races of 

 pigeon, such as a pouter and a f antail, are crossed, then 

 the offspring would on an average receive .5 of a unit 

 of determinants corresponding to each of the special 

 group of characters pouter and f antail, the same .99 of 

 a unit corresponding to the characters blue rock pigeon, 

 and 98.01 units corresponding to the characters species 

 pigeon. If, then, the determinants of pouter and fan- 

 tail do not to any great extent correspond, what wonder 

 is it that they more or less neutralise each other, and 

 allow the blue rock pigeon determinants to gain the 

 upper hand, and show their presence ? 



This view of the constitution of the germ-plasm may 

 at first sight seem contrary to the law of ancestral 

 heredity, but in reality it is not so. A man may receive 

 a quarter of his hereditary characters from each parent, 

 and a sixteenth from each grandparent, but all except 

 a very minute proportion of these characters are com- 

 mon to all men, they being, in fact, the characters 

 proper to the species Homo sapiens, as such. Instead 

 of a quarter of a unit from each parent, a man in reality 

 receives only a hundredth or a thousandth of a unit of 

 characters peculiar to the parent as such, all the rest 

 being the characters common to all members of the 

 race. Even this minute fraction of a unit does not in 

 any way represent characters acquired by the parent 

 during his life-time, but is itself built up of proportions 

 of peculiar characters received from his parents, grand- 



