VARIATION. 327 



antagonisms to multiform results. Whether they are or 

 are not the direct initiators, they must still be the indirect 

 initiators. 



§ 87a. In the foregoing sentence those pronounced struc- 

 tural variations from which may presently arise new varieties 

 and eventually species, are ascribed to " the larger functional 

 variations produced by greater external changes " ; and this 

 limitation is a needful one, since there is a constant cause of 

 minor variations of a wholly different kind. 



There are the variations arising from differences in the 

 conditions to which the germ is subject, both before detach- 

 ment from the parent and after. At first sight it seems that 

 plants grown from seeds out of the same seed-vessel and ani- 

 mals belonging to the same litter, ought, in the absence of 

 any differences of ancestral antecedents, to be entirely alike. 

 But this is not so. Inevitably they are subject from the very 

 outset to slightly different sets of agencies. The seeds in a 

 seed-vessel do not stand in exactly the same relations to the 

 sources of nutriment: some are nearer than others. They 

 are somewhat differently exposed to the heat and light pene- 

 trating their envelope; and some are more impeded in their 

 growth by neighbours than others are. Similarly with 

 young animals belonging to the same litter. Their uterine 

 lives are made to some extent unlike by unlike connexions 

 with the blood-supply, by mutual interferences not all the 

 same, and even by different relations to the disturbances 

 caused by the mother's movements. So, too, is it after 



separation from the parent plant or animal. Even the 

 biblical parable reminds us that seeds fall into places here 

 favourable and there unfavourable in various degrees. In 

 respect of soil, in respect of space for growth, in respect 

 of shares of light, none of them are circumstanced in quite 

 the same wa3'S. With animals the like holds. In a litter of 

 pigs some, weaker than others, do not succeed as often in 

 getting possession of teats. And then in both cases the 

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