LIFE-HISTORY. IxV 



on olfactory nerves, analogically one might suppose 

 that the sense of smell in insects might be effected 

 through the stomata, with their network of tracheae or 

 air-tubes, which permeate the bodies of all insects. 



A continual stream of air passes through their bodies. 

 This circulation is promoted by the contraction and 

 expansion of the body-rings, — a fact proved by the 

 rapid action of chloroform upon Tettigidag, and other 

 insects, the stupefying effects of which must be refer- 

 able to its absorption through these air-tubes. The 

 protecting strainers at the mouths of the stomata also 

 indicate that even gross particles are liable incon- 

 veniently to pass these entrances. 



Up to the present time, however, no special nerves 

 have been detected in contact with, or spreading over, 

 the tracheal walls or the stomata of insects, which can 

 be at all referable to the sense of smelling. Anatomists 

 have been driven to search elsewhere for olfactory 

 organs, which surely must exist in insects. 



Eeaumur, Lionet, Dufour, and more lately Sir John 

 Lubbock, all refer to the antennae for smelling 

 sensations, though the latter author thinks that 

 these parts may contain auditory, in addition to 

 olfactory, nerves. Newport, Wolff, Graber, and others, 

 believe that the antennas operate as hearing organs, 

 in which department of the senses I am myself 

 disposed to place them. 



Life-History. 



Although it is incumbent on the entomologist pri- 

 marily to show the affinities of insects one to another, 

 and to arrange and classify them, as far as may be, in 

 a natural manner ; yet to many, the occupation of 

 noting the habits and economy of any group he may 

 choose for his study is the more grateful task. Perhaps 

 no Order of the Animal Kingdom presents in this 

 respect more extraordinary traits than that of Insects. 



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