INSECTS IN GENERAL. 59 



being dissolved in liquids, first manifest their qualities on 

 that part of the animal where it was most required that they 

 should be appreciated, before coming into the interior of his 

 economy, for taste is one of the qualities of food." 



" In the final analysis, all the organs of sense are consti- 

 tuted by physical or chemical apparatus, true criterions to 

 which the nerves lead to produce, on the instant, a complete 

 idea of the sensation." 



M. Dumeril, after these physiological observations, which 

 he owns to be necessary for explaining the mode in which 

 the sensation of odours is produced in insects, goes on to cite 

 the facts which prove that they do possess this sensation. 

 His observations are interesting. 



" It appears that the object of Nature, in endowing with 

 existence this innumerable quantity of destructive beings, 

 was to employ them in clearing away the remains of organ- 

 ized beings deprived of life — thus restoring them sooner to 

 the mass of their component elements, to produce others, and 

 preserve unbroken the eternal circle of creation and destruc- 

 tion. 



" For this purpose she has bestowed on the being designed 

 for such operations, tastes, and a mode of life analogous to 

 the functions vhich they were called upon to fulfil ; and in 

 this instance, as in all her works, to produce the necessary 

 degree of perfection, she has gifted these animals with a 

 sense altogether fitted to the manner of their existence. 



" It is through the medium which they inhabit, that insects 

 are advertised of the presence of such bodies as may serve 

 for their nutriment. The air, surcharged with odorant ema- 

 nations, which are continually escaping from it, carries into 

 the respiratory organ all the molecules which it holds in sus- 

 pension ; it thus becomes the invisible guide of the animal, 

 which is seeking to supply its own wants. 



"The early observers of nature did not study with suit- 



