BLASTOGENIC VARIATIONS. 183 



mean number of bands was also greater, it being 10.04 

 as against 9.84. In a third sample collected from still 

 another locality, the variability was 1.455, but the mean 

 number of bands was only 8.77. Supposing, therefore, 

 equal numbers of specimens had been collected from all 

 three localities and combined, the variability would 

 have been about double the average variability of the 

 individual groups of plants. Supposing samples had 

 been collected from numerous and more widely sepa- 

 rated localities, so as to get a representative sample of 

 the whole species, then doubtless the variability would 

 have been much greater still. Individual variability 

 may therefore be only slightly smaller than local racial 

 variability, but it is very much smaller than specific 

 variability. 



What is true for plants is true also for animals. 

 Supposing that in the case of the middle classes of Eng- 

 lish society, the average variability of the stature of all 

 the offspring is only about 10 per cent, more than that 

 of the offspring of individual parents, then it is clear 

 that if we were to include also representatives of the 

 lower and of the upper classes in our sample, the aver- 

 age variability would be somewhat greater, perhaps 12 

 per cent. If we were to include representatives in due 

 proportions from all the continental nations, then the 

 variability might be 25 per cent, or more in excess, and 

 if from all the nations of the world, with African pyg- 

 mies on the one hand, and Patagonian giants on the 

 other, then it might be 50 per cent, greater, or even 

 more. 



Asexual Reproduction in Plants. In plants asexual 

 reproduction is very much more common than in ani- 



