176 



THEORY OF EVOLUTION 



limits of tlie race of fantail grandparents had 

 not a selected (surviving) lot been taken for 

 tlie figures given in the table. 



The preceding account attempts to point out 

 how I should prefer to interpret the problem 

 of selection in the light of the most recent Avork 

 on breeding. But I would give a very incom- 

 plete account of the whole situation if I neg- 

 lected to include some important work which 

 has led some of my fellow-workers to a very 

 different conclusion. 



Castle in j^articular is the champion of a 

 view based on his results with hooded rats. 



*iA,||AA 



t'lG. 88. Scheme to show classes of hooded rats used by 

 Castle. (After Castle.) 



Starting with individuals which have a narrow 

 black stripe down the back he selected for a 

 narrower stripe in one direction and for a 



