102 THE CAUSES WHICH PROPAGATE 



CHAPTER III. 



INSTRUMENTAL MUSIC CONSIDERED AS A MATERIAL AGENT IN 

 REPRODUCTION AND DISTRIBUTION. 



" Insects have, therefore, neither voice nor speech. They produce a sound, 

 however, by the internal hut not by the external air. For no insect respires, 

 but some of them utter a humming sound, as bees ; flies and others are said to 

 sing, as the cicadae. All these, however, produce a sound by the attrition 

 (vibration) of the internal air, which subsists within a membrane under the 

 division called the transverse septum, as, for instance, the kinds of cicada ; and 

 this is likewise the case with flies, bees, and all the rest, in consequence of 

 raising and depressing that membrane when they fly. For sound is produced 

 by the attrition of the internal air. But grasshoppers produce a sound through 

 the attrition of the legs by which they leap." — Aristotle, chap, ix., Book IV. 



As we have already observed^ among the first aspects that strike 

 those who study the economy of Nature are the various and 

 alternate seasons of rest and activity of which it is susceptible. 

 These are marked dial-like in the limber flowers or leaves that 

 during the day periodically expand and closCj in the lethargy 

 and flight of winged insects, no less than in the times of 

 repose and wakeful music of others. We have likewise here 

 not alone to treat of that harmony which confers a voice on the 

 summer earth and air, for neither does the insect population 

 beneath the crystal element remain wholly impassive at the 

 incense of the seasons ; and, considering the faculty of hearing 

 in water has been estimated to be four times as great as in 

 air, it must not altogether surprise us that the water insect 

 also swims and creaks purposely in the murmuring depth of 

 our parlour aquarium. 



Broadly speaking, Stridulation, or Instrumental Music, in the 

 Animal Kingdom, proper to Articulata, extends to Insecta, 

 Arachnida, and Crustacea. As regards Insecta, it characterises 

 the imagines, although exceptionally occurring in the pupal or 

 larval (?) stage. The musical organs sexually common in most 



