152 THEORY OF EVOLUTION 



crowded and in consequence dwarfed, while to 

 the left the same kind of corn has had more 

 room to develop and is taller. 



Darwin knew that if selection of particular 

 kinds of individuals of a population takes place 

 the next generation is affected. If the taller 

 men of a community are selected the average of 

 their offspring will be taller than the average of 



ft & 4440 



FIG. 77. Pedigree of boys shown in Fig. 76. (After 

 Blakeslee.) 



the former population. If selection for tallness 

 again takes place, still taller men will on the 

 average arise. If, amongst these, selection 

 again makes a choice the process would, he 

 thought, continue (fig. 79). 



We now recognize that this statement con- 

 tains an important truth, but we have found that 



