148 CHARLES DARWIN 



and bands in the broad sunshine before the admiring 

 and attentive eyes of their observant dames. He traces 

 up the same spirit of rivalry and ostentation to the 

 cock-pheasant strutting about before the attendant 

 hen, and to the meeting-places of the blackcock, where 

 all the males of the district fight with one another 

 and undertake long love-dances in regular tournaments, 

 while the females stand by and watch the chances 

 and changes of the contest with affected indifference. 

 Finally, he points out how similar effects are produced 

 by like causes among the higher animals, especially 

 among our near relations the monkeys ; and then he 

 proceeds to apply the principles thus firmly grounded 

 to the particular instance of the human race itself, the 

 primary object of his entire treatise. 



Some of the most interesting of the modifications 

 due to this particular form of selective action are to be 

 found amongst the insects and other low types of animal 

 life. The crickets, the locusts, and the grasshoppers, 

 for example, are all famous for their musical powers ; 

 but the sounds themselves are produced in the different 

 families by very different and quaintly varied organs. 

 The song of the crickets is evoked by the scraping of 

 minute teeth on the under side of either wing-cover ; 

 in the case of the locusts, the left wing, which acts as a 

 bow, overlies the right wing, which serves as a fiddle ; 

 while with the grasshoppers, the leg does duty as the 

 musical instrument, and has a row of lancet-shaped 

 elastic knobs along its outer surface, which the insect 

 rubs across the nerves of the wing-covers when it wishes 

 to charm the ears and rouse the affection of its silent 

 mate. In a South African species of the same family, 



