40 



Riley — Presidential A ddress. 



j)e:iii //. Iiccfiis L. and our own //. hchrciisi Stretch. The 

 possession oi odoriferous glands, in otlier words, implies the 

 ])ossession of olfactory organs. Yet there is among insects no 

 one specialized olfactory organ as among vertebrates; for while 

 there is conclusive proof that this sense rests in the antenna' 

 with many insects, especially among Lepidoptera, there is good 

 evidence that in some Hymenoptera it is localized in an ampulla 

 at the base of the tougue, •while Gi'aber gives reasons for believ- 

 ing that in certain Orthoptera (Blattida^) it is located in the anal 

 cerci, and the ])alpi. 



Fiit. 9. — Sensory Okgajss in Insects : A, scuoOiy pits 011 aiucmise of yoiiiia; wing 

 less Aphis peisiccr-Higcr (after Smith) ; y> , orgau of smell iu May Beetle (after Hauser) ; 

 C, organ of smell in Vespa (after Hauser) ; D, sensory organs of TeimesJ/avipes, a, tibial 

 auditory organ, c, enlargement of same, b, sensory pits of tarsus (after Stokes); E, organ 

 of taste in maxilUe of I'espa vuli^aris (after Will) ; F, organ of taste in labium of same 

 insect (after Will); 6", organ of smell in Caloptenus (after Hauser); H, sensory pilose de- 

 pressions on tibia of Termes (after Stokes) ; /, terminal portion of antennre oi Myrmica 

 rug^iiiodis, c, cork shaped orgaus, s, outer sac, /, tube, w, posterior chamber (after I<ub- 

 bock) ; K, longitudinal section through portion of flagellum of antennae of worker bee, 

 showing sensory hairs and supposed olfactory organs (after Cheshire). — All very greatly 

 enlarged. 



Hp:aring. — In regard to the sense of hearing the most casual 

 e.Kperimentation will show (and general experience confirms it) 

 that most insects, while keenly alive to the slightest movements 



