358 THE HUMAN SPECIES 



harmonies and discords succeed each other, by the simultaneous 

 production of several notes, and when, on the other hand, in 

 the course of various musical productions, a definite accen- 

 tuation of tone recurs at regular intervals of time (rhythm) " 

 (Wundt). 



It may again be pointed out that instrumental music is no 

 monopoly of the human race, as when the drum, tambourine 

 and rattle were added to the musical instruments employed by 

 man, the corresponding instruments used by animals could 

 everywhere be seen and heard. Woodpeckers drum, tapping 

 on a bough with a rapid succession of blows with the beak 

 delivered with a swinging movement ; the North American 

 woodcock (Tetrao umbellus) drums, beating his wings together 

 across his back. The cockbird of the black West African 

 weaver-bird glides with quivering wings through the air and 

 so produces a rapid whirring noise like that of a child's rattle. 

 Many male goatsuckers during the breeding season make a 

 peculiar buzzing noise when flying through the air. Storks 

 produce a clapping sound by shutting their bills ; peacocks and 

 birds of paradise rustle the quills of their plumage ; the male 

 lapwing combines vocal and instrumental music by first draw- 

 ing in the air, and then in a moment blowing it out again, at 

 the same time striking the end of his beak straight on to a 

 stone, or tree-trunk. Becassines have a number of tail feathers 

 specially arranged so that in their rapid flight through the air a 

 remarkable whirring, humming, or even clattering sound is pro- 

 duced ; the cock Chamaepetes unicolor in America, the Indian 

 Florican (Sypheotides aurita), and a species of pipra have a 

 similar mechanism in their wing feathers. 



Certain arthropods are keen musicians. The males of 

 several kinds of Theridia (spiders) are able to make a kind of 

 whirring noise. The buzzing of Diptera and Hymenoptera is 

 not a mere involuntary result of the movements of the wings 

 in flying, but a voluntary act, produced by squeezing the air 

 out of the trachea. The death's head moth (Acherontia atropos) 

 makes its shrill piping noise by rubbing its proboscis upon the 

 strong ridges on the inner surfaces of its antennae. The dron- 

 ing of chafers can be heard at a great distance and is mainly 

 due to the rasp a part of the body marked with paralell ridges, 



