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 civilized 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, oy of a beast of prey, or of 



a herbivore persecuted by the beast of ]yi'ey. And this is by no means 



due solely to the invention of spectacles, but in a much greater degree 



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



numerous possil)ilities 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 lal )Our 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 partly because of the mingling with normal sight, but partly 



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



determinants concerned, a variation in a downward direction was 



bound to set in, and Avill continue until a limit is set to it b}^ personal 



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



of e^'e-deterioration ; and the resistance to it is somewhat inhibited 



in its operation, because although individuals with extremely 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 always 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 ' longest school form ' and of the greatest number of 

 sjDCctacle-wearers, short-sight is still usually acquired b}^ individuals, 

 althougli 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 e3^es 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 tlie fact that 



