SELECTION 173 



when he wrote, "it is not probable that she 

 consciously deliberates ; but she is most 

 excited or attracted by the most beautiful, 

 or melodious, or gallant males." We do not 

 know very clearly what choosing may mean 

 to a hen-bird; but even when she seems to 

 choose some slight improvement in colour or 

 song or dance, the probability is that she is 

 simply surrendering herself to the male whose 

 tout ensemble has most successfully excited 

 her sexual interest. 



GERMINAL SELECTION. In 1895 Weismann 

 suggested that the concepts of " struggle " 

 and " selection " might be usefully extended 

 to the individual items which compose the 

 germ-plasm, or, what comes to the same thing, 

 the inheritance. If we suppose, as there are 

 many reasons for supposing, that the physical 

 basis of inheritance in the germ-cells is com- 

 posed of a multitude of representative vital 

 particles which are able to feed, grow, and 

 multiply, then it is conceivable that fluctua- 

 tions in the nutritive supply of the germ-cells, 

 and inequalities in the vigour and assimilating 

 power of the hereditary constituents, may 

 result in an intra-germinal struggle and 

 selection. 



The general idea is a familiar one, that 

 nothing succeeds like success; and vice versa. 



