Pearson's Investigations 



on spiders, in a state of nature. Such observa- 

 tions demonstrate that selective mating occurs 

 in nature, but, for the most part, fail to show what 

 it is that determines the choice. 



D. Dewar, however, states (Birds of the Plains, 

 p. 42) that the coloured peahens in the Zoo- 

 logical Gardens at Lahore show a decided pre- 

 ference for the white cocks, which are kept in 

 the aviary along with normally coloured cocks. 

 He gives it as his opinion that "the hens select 

 the white cocks, not because they are white, but 

 because of the strength of the sexual instincts of 

 these latter. The white cocks continually show 

 off before the hens ; the sexual desire is developed 

 more highly in them than in the ordinary cocks, 

 and it is this that attracts the hens." 



The only zoologists who have investigated 

 experimentally the question of sexual selection 

 appear to be Karl Pearson and Frank Finn. 

 The former tried to determine, by actual measure- 

 ments, whether there is any preferential mating 

 among human beings as regards physical char- 

 acteristics. " Our statistics," he writes, on page 

 427 of The Grammar of Science, "run to only 

 a few hundreds, and were not collected ad hoc. 

 Still, as far as they go, they show no evi- 

 dence of preferential mating in mankind on 

 the basis of stature, or of any character very 

 closely correlated with stature. Men do not 

 appear, for example, to select tall women for 



39 



