THE CHARACTERISTICS OF INSECTS. 



2 35 



ing the nervous filaments spread over their centers. These ani- 

 mals are not entirely insensible to the action of light ; for they 

 shrink from it and exhibit signs of being disagreeably affected 

 when they are exposed to it. 



The faculty of hearing is greatly developed among insects. 

 The slightest noise disturbs them yet the position of the organ 

 of hearing has not been well 

 defined. Maurice Girard* as- 

 sumes that its seat is in the 

 antenna? ; and in the absence 

 of a special organ, that it acts 

 like a flexible rod, free at one 

 end, and attached by the other 

 end to an elastic membrane. 

 M. Kiinckel agrees with Muller 

 and Siebold that the organ of 

 hearing is situated outside of 

 the head. 



The smell and the taste, on 

 the other hand, belong entirely 

 to the cephalic region. The 

 taste is seated near the mouth ; 

 the smell is one of the appan- 

 ages of the antennas. This has 

 been irrefutably demonstrated 

 by M. Balbiani, who, taking a 

 number of newly hatched male silkworm moths, and isolating them 

 from contact with females, divided them into two lots, which he 

 placed in different boxes. One of the lots was left undisturbed, 

 the other was subjected to experiments. The pectinal antennas of 

 all the individuals in it were cut off at the roots. On bringing 

 tables on which were females near the boxes containing undis- 

 turbed moths, the insects were observed, even at a distance of 

 several yards, to beat their wings and become violently agitated. 

 But when females were brought near the moths that had been 

 deprived of their antennas, they showed no signs of being af- 

 fected ; their wings remained flat and motionless. The strong 

 exhalations from the females were imperceptible to them ; the 

 removal of their antennas had deprived them of the power of 

 smelling. f Other naturalists, however, give the power of per- 

 ceiving odors to the stigmata. 



Locomotion is performed in insects, as in vertebrates, by means 



Fig. 16. Nervous System of the Adult Bee. 

 (After E. Blanchard, Metamorphoses.) 



* Maurice Girard, Traite d'Entomologie, comprising the history of useful species and 

 their productions, and of injurious species and the means of destroying them. 



f Brehm, Les Insectes. French edition, by J. Kiinckel d'Herculais. Paris: J. Bailliere 

 et fils. 



