462 SCIENCE PROGRESS 



in the cave fish, their power of sight has been lost. Innumerable 

 similar examples are available. Some characters disappear more 

 rapidly than others in, the absence of selection ; but there is no 

 need to discuss this point here. 



There can be no doubt that mental as well as physical charac- 

 ters are subject to selection by the action of the environment. 

 Take the example of a pointer. Very likely a bulldog might be 

 taught to point but there cannot be the slightest doubt that 

 pointers generally are more easily taught to point than are bull- 

 dogs. The efficiency of pointers as pointers is maintained only 

 by the very stringent way in which selection is exercised by the 

 breeder ; their mental characters are just as much subject to 

 selection as the shape of their heads : those animals are most 

 sought after to breed from which have proved themselves to 

 possess the greatest power of displaying the mental characters 

 involved in pointing ; the characters involved in pointing have 

 been produced by selection from a common ancestor of the 

 pointer and the bulldog in comparatively recent times. 



Among men, a very good example exists in the case of the 

 Jews. During hundreds of years, they were subjected to most 

 stringent selection — a selection which still continues to operate 

 to some extent in some countries. They were not allowed to 

 carry arms when every man went armed, so that any Jew who 

 showed any signs of combativeness or desire to resist oppression 

 by physical violence must have been eliminated at a very early 

 stage in his career and can have had but little chance either of 

 having or of bringing up children. Before they were dispersed 

 and subjected to this very stringent selection, the Jews were 

 probably the most quarrelsome, bloodthirsty and combative race 

 known to history. I think it would not be going too far to say 

 that they are now among the most peaceful. At the same time 

 the selection to which they were thus subjected has acted upon 

 their mental character in other ways. It was only by the exer- 

 cise of great intelligence that individuals were able to survive ; 

 the stupid must have been eliminated, only the clever could 

 escape. The result is that the Jews to-day probably possess a 

 higher average of intelligence than any other race in the world ; 

 but only in peaceful pursuits, for we do not hear of great soldiers 

 and sailors among them. I would here emphasise the fact that I 

 am speaking in general terms. I do not mean that there are no 

 combative or quarrelsome Jews but that on the average the race 



