EXERCISE 443 



or a tailor ; we may use our legs much or little as compared to 

 our arms ; during childhood we may have opportunities of indulg- 

 ing in many active games, or we may be cramped in a factory or 

 the slums of a great city. Though the diet of the navvy may be 

 less appetizing than that of wealthier people, yet it is usually 

 sufficient in all essentials to secure full physical development. 

 Not so the work of the clerk or the tailor. It follows, that when 

 individuals, especially individuals belonging to different sections 

 of the community, differ in those characters which develop under 

 the stimulus of use, the difference is less certainly founded on 

 germinal differences than when they differ in the characters which 

 arise under the stimulus of nutriment, for example, eye-colour. 



726. Probably, on the average, some sections of the community, 

 for instance the men of the leisured classes who take plenty of 

 exercise, develop under the stimulus of use nearly as well as their 

 capacities permit. It is quite certain, I think, that other sections, 

 for example, clerks and slum-dwellers, would, under other condi- 

 tions, develop better than they actually do. In the case of ' use- 

 acquirements/ unlike ' inborn ' traits, it is evident, then, that there 

 is scope for considerable physical improvement in certain classes 

 without any resort to selection. But, here again, the means of 

 securing improvements are so obvious as to be non-controversial. 

 Therefore they need not be discussed at length. The debated 

 point is the extent to which slum-dwellers, for instance, owe their 

 physical inferiority, on the one hand, to the conditions under 

 which the individuals are reared, and, on the other, to germinal 

 peculiarities which, as is alleged, constitute them an instrinsically 

 degraded race. Speaking generally, biometricians assume that the 

 inferiority is germinal and, therefore, beyond cure except by selec- 

 tion. Medical men believe it is partly acquired, partly due to the 

 inheritance of parental acquirements, and partly a consequence of 

 the direct action of the environment on the germ-plasm of un- 

 fortunate or vicious parents. Believing that good surroundings 

 cause intrinsic racial improvement and bad conditions degenera- 

 tion, they suppose that only a prolonged revival of good conditions 

 will remove the degeneracy. To me it seems overwhelmingly 

 probable that slum-dwellers, factory hands, and the like, are 

 physically inferior, not because they are as a class incapable of 

 developing as well as the best sections of the community, but 

 mainly, if not solely, because their surroundings are such that they 

 have not had the chance of developing as well as they might. I 

 think we have only to improve their surroundings sufficiently and 



