VARIATIONS 77 



librium as if by a leap. We thus get the contrast between 

 "continuous" variations small in amount, and "discontinuous" 

 or " transilient " variations in which a step of considerable 

 dimensions is taken with apparent suddenness. 



Variations considered in relation to the Character of 

 Antecedent Generations. — The term variation, used concretely 

 to denote an organic peculiarity or idiosyncrasy, is obviously a 

 relative term, implying some standa.rd of comparison. It is a 

 deviation from the parental type, a divergence from the mean 

 of the stock. 



In many cases, a variation may be described as simply an 

 incompleteness in the inheritance or in the expression of the 

 inheritance. The divergence from the norm is due to the sup- 

 pression or inhibition of some character. This may be illustrated 

 by a perfectly white (albino) baby, born to almost coal-black 

 parents.* If such a form became the founder of an albino 

 race, as in the case of rats and mice, we should be justified in 

 concluding that the particular material organisation which 

 eventually leads to the deposition of pigment in the body had 

 somehow dropped out of the inheritance. If the albinism was 

 in no respect transmitted to the next generation, we should be 

 justified in concluding that the structural arrangements which 

 lead on to pigmentation had simply been hindered from finding 

 their normal expression in development. 



A minus variation like albinism may be described as due to 

 an incompleteness in the inheritance or in the expression of the 

 inheritance, but there are other variations which must, so to 

 speak, bear the plus sign, for they involve the augmentation or 

 exaggeration of a character. Plus variations of this sort have 



* " Its father and mother were horrified ; their friends and relations, 

 in fact all the villagers, were called to examine and criticise it. Why such 

 surprise ? Why such commotion ? The answer is self-evident : the law 

 of heredity had been broken." — R. W. Felkin. The vulgar mind is always 

 impressed by size and quantity ; big deviations strike the imagination, 

 and the normal occurrence of small deviations is forgotten. 



