2G6 THE PLAY OF ANIMALS. 



when the animal making it is intelligent enough to be 

 conscious of self-exhibition. "With mammals," says 

 Darwin, " the male appears to win the female more 

 through the laws of battle than through the display 

 of his charms," * but he adds a long list of sexual stim- 

 uli. Nowhere, however, do I recall a description by 

 him or another where a mammal attempted to draw 

 attention to his excited condition by movements, with 

 the single exception of monkeys. Indeed, Darwin says 

 that proof is wanting that the males of mammals make 

 any effort to display their charms to the female, f 



But perhaps the actions described in the section on 

 courtship arts, such as the dog's erect carriage, his wav- 

 ing tail and stiff legs, are partly to show his physical 

 advantages, and we read how the stone marten raised 

 his hair, and the fish otter played with his eel-like tail. 

 I have often noticed, too, that dogs who wish to be es- 

 pecially friendly have a way of turning their back to 

 the stranger, which is like the habit of the apes, for the 

 dog often has striking tufts of hair on his hind parts. 



We now take up birds again. All the different mo- 

 tions that we have seen described are useful to the bird 

 in displaying his form and colouring. When the reed 

 warbler takes his downward plunge in the air his feath- 

 ers are inflated till he looks like a ball. The beauti- 

 ful Madagascar weaver bird flutters like a bat, with 

 trembling wings, about the modest gray female. Nau- 

 mann says of the blue titmouse: " Hopping busily 

 about in the bushes, swaying on slender sprays, etc., the 

 male dallies with his mate, and at last floats from one 

 tree top to another, sometimes forty feet away, where the 



* Descent of Man, chap. xyii. 

 f Loc. cit. 



