212 THE COURTSHIP OF ANIMALS 



among the birds, or the beetles among the insects, his 

 interpretation of the action of sexual selection, it is 

 more than probable, would have been materially different 

 from that developed in the " Descent of Man." No 

 additions of any importance have been added to the facts 

 he so laboriously collected. 



As touching the " horns " it should be remarked that 

 these may arise either from the head or from the thorax, 

 or from both, and sometimes even from the under surface 

 of the body. 



One of the most remarkable instances of these singular 

 outgrowths is that of the Hercules Beetle {Dynastes 

 hercules), of the West Indies and tropical America. 

 Herein the roof of the head is prolonged into a great 

 upturned beam bearing tooth-like prominences, and 

 the top of this is opposed to a still more massive beam, 

 whose base covers the whole roof of the thorax, and 

 whose tip extends far beyond that projecting from the 

 head. A pair of " teeth " point downwards from the 

 middle of this beam, whose under surface is thickly 

 covered with short chestnut-coloured hairs forming a 

 brush-like surface. In another, Copris isidis, the head 

 bears two short, rhinoceros-like horns, and the thorax 

 a short, triangular overhanging ledge : in Phancsus Jaunus 

 there is a single horn on the head, and the thorax bears 

 two short, forwardly-projecting blades, one on each side ; 

 while in Onthophagus rangijer — the Reindeer Beetle — 

 the head bears a pair of horns curiously like the antlers 

 of a deer. One might cite many such instances, all 

 varying in detail, but these will suffice. 



Darwin, in commenting on these structures, remarked : 

 " Th£ extraordinary size of the horns and their widely 

 different structure in closely-allied forms indicate that 



