84 VARIABILITY 



become yellow, and in their now rounded form they approached 

 the common Europeon maize. In the third generation nearly all 

 resemblance to the original and very distinct American parent was 

 lost. In the sixth generation the maize perfectly resembled a 

 European variety." 1 " Clayton allowed six bean plants to grow in a 

 spot where they would catch all the sunshine of the day, while six 

 other similar plants were protected by a boarding which effectually 

 screened off the sun. When freshly gathered in October, the 

 weight of the beans and the pods of the exposed plants was to that 

 of the protected as 99 : 29, whilst the weight of the day beans was 

 as 1 6 : 5. The next year the weight of the fresh beans and pods 

 obtained from the sunshine-grown seeds of the previous year, 

 was half as much again as in the case of the plants from shade- 

 grown seeds, in spite of the fact that all of the plants were now 

 grown in sunshine and under precisely similar conditions. In 

 the fourth year plants with an exclusively shady ancestry pro- 

 duced flowers but failed to mature fruit." 2 European dogs are 

 said to deteriorate steadily in India, and English horses in the 

 Falklands. 



135. It is unnecessary to multiply examples. Obviously some 

 of this evidence is capable of an interpretation different from that 

 given by its observers. For example, the medical statistics are 

 wholly inconclusive. Not only diseased and intemperate, but 

 healthy and temperate people have defective offspring ; whereas 

 diseased and intemperate people often have normal children. It 

 has not been shown that the proportion of defective offspring is 

 greater in the one case than in the other. 3 Even if that were done 

 it would still have to be shown that the parents were not themselves 

 defective before they became drunken or diseased; for it is 

 roundly asserted that people naturally (i.e. innately) defective, 

 mentally or physically, are especially prone to intemperance and 

 disease, and, of course, the offspring of such people tend, in any 

 case, to inherit their defects. 4 Next it would have to be proved 

 that the defects of the children were true variations, true alterations 

 of the hereditary tendencies reproducible by descendants, not 

 merely modifications caused by temporary injury (due to the health 

 or habits of the parents) to the germ-cell, embryo, or foetus. In the 

 case of slum-bred children, also, it has not been shown that the 



1 Op. cit., vol. i. p. 340. 



2 Vernon, Variations in Animals and Plants, p. 247. 3 See 776-7. 



4 See, for example, Branthwaite, The British Journal of Inebriety, January 

 1908. 



