BLASTOGENIC VARIATIONS. 125 



more fundamental and far-reaching than its author 

 claimed it to be. Thus he says, " If Mr. Galton's law 

 can be firmly established, it is a complete solution, at 

 any rate to a first approximation, of the whole problem 

 of heredity." Professor Pearson points out that by 

 means of it we are enabled to find the coefficients of cor- 

 relation between an individual and any individual an- 

 cestor, and that these coefficients in their turn will 

 suffice to determine all inheritance, whether direct or 

 collateral. 



As regards the relation of this law of heredity to 

 variations produced by amphimixis, it is necessary to 

 emphasize one fact, viz., that it concerns only the 

 average contributions of ancestors to offspring, and not 

 the absolute contributions. Within what limits the 

 contributions of each parent and grandparent to the 

 heritage of a child may vary, nothing whatsoever is 

 known. It is possible that they may be very wide in- 

 deed, and everyday experience tends to give colour to 

 this view. How trite is the expression that such and 

 such a child is the " image ' of his father or mother, 

 whilst instances are no less common in which it is diffi- 

 cult, if not impossible, to trace any distinct resem- 

 blance between parent and child. Such cases as these, 

 even if they could be substantiated by exact physical 

 measurements, would in reality prove but little. It 

 would be impossible to make accurate comparisons of 

 all the tissues and organs of the body, and of the cells 

 composing them, and it might be that these unexamined 

 and unexaminable portions of the organism in reality 

 possessed a very close correlation with the correspond- 

 ing parental tissues. The average degree of correla- 



