112 AUDITORY RODS IN BEETLES. 



Special sense-organs occur also on the wings of other 

 insects. Hicks fouud them " most perfect in the Diptera, 

 next so in the Colenptera, ratlier less so in the Lepidop- 

 tera, but slightly developed in the Neuroptera, scarcely 

 at all in the Orthoptera (though this assertion may be 

 liereafter modified), and that only a trace of them exists 

 in the Hemiptera." They are similarly constituted and 

 equally developed in both sexes. Hicks regarded them 

 as organs of smell. Ley dig,* on the contrary, considered 

 them as auditoiy organs. His mode of preparation dis- 

 played better the structure of the nerves, and he found 

 that tliey end in peculiar, club-shaped rods [Stabchen 

 Oder Stafie), closely resembling those in the ears of 

 Orthoijtera. He observes that, as in the case of the 

 tibial auditory rods of Orthoptera these rods are of 

 two sorts, which are arranged separately, those in one 

 part of the organs being shorter and blunter, those in 

 another more pointed and elongated. Bolles Lee, on 

 the contrary, considers that the supposed existence of 

 two forms, pointed and rounded, is merely due to an 

 optical deception, and that in reality they are all 

 similar. Leydig also observed in some cases that the 

 rods were thrown into fine ridges. He found also 

 somewhat similar papillje on the front wings of certain 

 insects, but could not detect in them the characteristic 

 nerve-ends. It must be confessed that the base of the 

 wing would not seem a convenient place for an organ 

 of hearing. The movements of the wing, it might 

 well be supposed, would interfere with any delicate 

 sensations. Still, this objection would apply to almost 

 any sense being thus placed. 



" Auditory rods " are now, moreover, known to occur 



* MUlIer's Archie, I860. 



