56 



ANTENNAL ORGANS OF INSECTS. 



Kraepelin* and Sazepinf liave also publislied valuable 

 memoirs containing many interesting details. 



The hairs of the antennse, then, serve some for touch 

 and some for smell, while there is, as we shall presently 

 see, strong reason for supposing that the sense of 

 hearing is also in some insects seated in the antennae. 



The greatest variety of antennal organs, so far as we 

 yet know, occurs in the Hymenoptera (ants, bees, and 

 wasps). Of these I give a diagrammatic figure. 

 There are at least nine different structures. 



1. Ordinary hairs (Fig. 43, c). 



y\-V'-\^J-— 



Fig. 43.— Diagram showing structures on the terminal segments of the antenna of 

 insects, a, Chitinous cuticle ; Z>, hypodermic layer ; c, ordinary hair ; d, tactile 

 hair ; e, cone ; f, depressed hair, lying over g, cup, with rudimentary hair at the 

 base ; h, simple cup ; i, champagne-cork-like organ of Forel ; k, flask-like organ ; 



1, papilla, with a rudimentary hair at the apex. 



2. Hairs of touch (Fig. 43, d). 



* " Phys. und Hist. Uut. ii. die Geruchsorgane der Iiisekten," Zeit, 

 fur TFz'ss. Zool.^ 1880; and " Ueber die Geruchsorgane der Glieder- 

 thiere," 1883. 



t " Ueber den histol. Ban und die Vert, der nervosen Endorgane 

 auf den Fiihleru der Myriopoden," M€m. de VAcad. Imiie'r. de Sc. de 

 St. Petersburg, 1885. 



