PERPETUATION OF LIVING BEINGS. 119 



that the characters of these races go very far deeper 

 — they extend to the bony structure^ and to the cha- 

 racters of that most iuiportant of all organs to us — the 

 brain ; so that^ among men belonging to different races, 

 or even within the same race, one man shall have a 

 brain a third, or half, or even seventy per cent, bigger 

 than another; and if you take the whole range of 

 human brains, you will find a variation in some cases 

 of a hundred per cent. Apart from these variations in 

 the size of the brain, the characters of che skull vary. 

 Thus if I draw the figures of a Mongul and a Negro 

 head on the blackboard, in the case of the last the 

 breadth would be about seven-tenths, and in the other 

 it would be nine-tenths of the total length. So that 

 you see there is abundant evidence of variation among 

 men in their natural condition. And if you turn to 

 other animals there is just the same thing. The fox, 

 for example, which has a very large geographical 

 distribution all over Europe, and parts of Asia, and 

 on the American Continent, varies greatly. There are 

 mostly large foxes in the North, and smaller ones in 

 the South. In Germany alone, the foresters reckon 

 some eight different sorts. 



Of the tiger, no one supposes that there is more 

 than one species ; they extend from the hottest parts of 

 Bengal, into the dry, cold, bitter steppes of Siberia, 

 into a latitude of 50°,— so that they may even prey 

 upon the reindeer. These tigers have exceedingly 

 different characteristics, but still they all keep their 

 general features, so that there is no doubt as to their 

 being tigers. The Siberian tiger has a thick fur, a 

 small mane, and a longitudinal stripe down the back, 



