56 



ANTENNAL ORGANS OF INSECTS. 



Kraepelin* and Sazepint have also published valuable 

 memoirs containing many interesting details. 



The hairs of the anteuoBe, 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). 



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

 insects, a, (.'hithious cuticle; b, hypodermic layer; c, ordinary hair; </, tactile 

 bair ; c. cone ; /, depressed hair, lying over r/, cup, with rudiuientary hair at the 

 base ; //. simple cup ; ?', cbampagne-cork-lilte organ of Forel; k, flask-like oi'gau ; 

 I, papilla, with a rudimentary bair at the apex. 



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



* " Phys. und Hist. T^ut. ii. die Geruchsorfjane der Ineekten," Zeit. 

 fin- Whs. Zool., ISSO , and " Ueber die Geruchsorgane der Glieder- 

 thiere," 1883. 



t " Ueber den histol. Bau nnd die Vert, der nerTosen Endorgane 

 anf den Piiblern der Blyriopoden," Mem. de I'Acad. Impdr. de Sc. de 

 St. Fdershurg, 1885. 



