146 THE EVOLUTION THEORY 



ceaseless fluctuations within the germ-plasm — germinal selection — 

 affords a better explanation than the other theory was ever in 

 a position to offer. At that time I pointed out that the survival of 

 the individual among ci\ilized races had not for a very long time 

 depended on the perfection of his eyesight, as it does for instance in 

 the case of a hunting or warlike Indian, or of a beast of prey, or of 

 a herbivore persecuted by the beast of prey. And this is by no means 

 due solely to the invention of spectacles, but in a much gi-eater degree 

 to the fact that every man no longer has to do everything, so that 

 numerous possibilities of gaining a livelihood remain open to the less 

 sharp-sighted ; that is, the division of labour in human society has 

 made the survival of the short-sighted quite feasible. As soon as this 

 division of labour reached such a degree that the founding of a family 

 offered no greater difficulty to the short-sighted individual than to 

 one with normal sight, short-sightedness could no longer be eliminated ; 

 and j)artly because of the mingling with normal sight, but partly 

 also because of the never- failing minus-fluctuations of tlie germ-plasm 

 determinants concerned, a variation in a downward direction was 

 bound to set in, and will continue until a limit is set to it by jDersonal 

 selection. Meantime, we are obviously still in t-he midst of the process 

 of eye-deterioration : and the resistance to it is somewhat inhibited 

 in its operation, because although individuals with extremelj^ bad 

 sight are for the most part hindered from gaining an independent 

 livelihood and having a family, this is certainly, thanks to our 

 mistaken humanity, not alwaj^s the case. There are even instances of 

 marriage between two blind persons ! 



As yet, however, the deterioration of eyes has not advanced very 

 far ; not nearly all families are affected by it, and even in Germany, 

 the land of the ' lono-est school form ' and of the e;i"eatest numi )er of 

 spectacle-wearers, short-sight is still usually acquired by individuals, 

 although there must frequently be a more or less marked predis- 

 position to it. It is a common objection to this view that in England, 

 France, and Italy the percentage of short-sighted individuals is much 

 lower, and, in point of fact, one sees far fewer people wearing 

 spectacles in those countries. This, however, does not prove that 

 a similar deterioration of eyes has not begun there also, for how could 

 the small inherited beginnings be detected if they were not accentuated 

 by the spoiling of the eyesight in the lifetime of the individual by 

 much reading of bad print, and by writing with l)ent head, as is 

 still too often the case in many German schools. 



That our interpretation, through panmixia on a basis of 

 germinal selection, is the correct one, we infer also from the fact that 



