IN SECT A. 33 



the body through the buoyancy of heated air which 

 they contain. The bodies of all insects are also not 

 burdened by heavy internal supports like the bones of 

 Vertebrates. 



The wings, when acted upon by the leaping-legs, 

 produce the musical notes or strigillations peculiar to 

 locusts. As a rule with insects the males strigillate, 

 and the females are mute. The genus Ephippiger of 

 the family Locustidae, however, is an exception to 

 this rule, as both sexes are provided with a musical 

 apparatus.^ The teeth on the inner side of the femur 

 (PI. II., Fig. 13, p. 38 ; //' ; a, b, different views of the 

 same magnified) are rubbed up and down against the 

 outer veins of the wing-covers.^ Mr. S. H. Scudder 

 found that certain insects would respond to the " mock 

 chirping" produced by playing upon a common steel 

 file with a quill, and by determining the pitch of the 

 note of the different species and their rate at different 

 parts of the " song," he was able to apply musical no- 

 tation, and give musical expression to the '* Songs of 

 the Grasshoppers." "^ 



The appendages of the abdomen are the three pairs 

 of organs which form the ovipositor (PI. I., Fig. 3, <5'i' ; 

 Fig. 9, os\ os", os'", p. 10). The ends of the upper pair 

 (Fig. 9, os') curve upward, and those of the lower pair 

 (os") downward ; between these is a smaller pair {os'") . 

 PI. II., Figs. 24, 25, 26, p. ^8, represent two stages 

 (Fig. 26 side view of second stage) in the develop- 



1 See Westwood, Introduction to Modern Classification of 

 Insects, Vol. I., p. 453, 



2 See for description of other modes of strigillation pp. 107, 132. 

 ^ American A-atiiralist, Vol. II., p. 113. 



