VARIATIONS. 27 



This blending of the parental characters, which we 

 see is capable of endless variety, is often very con- 

 siderably fettered by the fact that all characters are 

 not equally potent ; generally speaking, those more 

 recently acquired are not transmitted with the same 

 certainty that those of long standing are. These latter 

 are said to have gained a "prepotency" by long 

 descent; by repeated transmission they have become 

 fixed and prominent characters in the family, and the 

 presence of one such character in a parent tends to 

 materially limit variety in the offspring. But we shall 

 consider this subject later on, when we have learnt 

 something of how "acquired characters" affect the 

 family. 



Again, it should be pointed out that what are com- 

 monly looked upon as most striking variations in the 

 family, are often, in reality, not variations at all, but 

 reversions. In such cases the branch of the family to 

 which the parent belongs has, in consequence of some 

 combination of circumstances, deviated from, the family 

 type. With each generation the divergence has in- 

 creased, but it has not gained any fixity, and with the 

 infusion of fresh blood the offspring " throws back " 

 to the original family type. It is looked upon as a 

 variation, whereas it is a fair representative of the 

 family, and it is the parent who is at fault. But this 

 subject of reversion we shall also postpone for a short 

 time, while we endeavour to see what effect is exerted 

 upon the race by the environment that is, the action 

 of the whole outer world. 



