EVOLUTION 



1009 



ages and sex would tend to fallacy. Similarly in registering "observed 

 differences", which are simply to be measured, it becomes very im- 



FiG. 171. 



Gallon's Apparatus to illustrate the formation of a curve of frequency by 

 pellets falling fortuitously through the pegs of the upper part of the 

 box into the compartments beneath. A, the mouth of the apparatus, 

 and B the baffles narrowing the neck. 



1075 1125 1175 1225 1275 1325 1375 1425 1475 1525 /575 1625 1675 1725 1775 



Fig. 172. 



Figure to illustrate the curve of frequency so often shown by the variations 

 of a species. From Pearl. The particular curve refers to the brain-weights 

 of adult male Swedes. The basal figures indicate grammes; the vertical 

 figures indicate the number of individuals. 



portant to go on to try to distinguish "modifications" (directly due 

 to peculiarities of nurture) from "variations" (outcrops of germinal 

 VOL. II T 



