BEETLES THAT "BLUFF" 217 



Beetles are creatures of solitary habits ; how, then, 

 do they find their mates when, by the insistence of the 

 reproductive desires, they are driven forth to begin the 

 search ? Though we have no direct evidence, it seems 

 more than probable that, as with the Butterflies and 

 Moths, scent furnishes their most reliable guide. At 

 any rate, in a large number of species, as among the 

 Lamellicornia, the antennae bear leaf-like plates, which 

 are much more developed in the males, in which they 

 probably serve as scent-detecting organs. 



In some species stridulating organs occur such as are 

 met with in even greater perfection among the Crickets 

 and Grasshoppers, and among the Spiders and Scorpions. 

 That these " musical-boxes " provide a means of com- 

 munication between the sexes there can be no doubt, 

 even if, as some contend, they are commonly used only 

 to frighten enemies. This purpose may well be the 

 explanation of their presence in the larval Stag Beetle, 

 for it cannot be claimed that they have any relation 

 to the acts of courtship at this stage of develop- 

 ment. 



Stridulating organs, wherever they are met with, are 

 fashioned on the same principle. The mechanism for sound- 

 production differs conspicuously from that which produces 

 the voice in the vertebrates. For where there are no 

 lungs or breathing apparatus, comparable to that of 

 birds and beasts, there can be no internal voice-mechanism. 

 Instead, the skeleton which in these creatures forms the 

 external surface of the body — that is to say, it encloses 

 the muscles, whereas in the vertebrates it is internal and 

 overlain by the muscles — produces the necessary sounds. 

 And this by means of rubbing two opposed surfaces against 

 one another, one of which is ridged, the other toothed. 



