OLFACTOEY ORGANS OF WASP. 



55 



in fact, a fine hair, inverted over one of the usual 

 pits. 



In 1880 Hauser published an excellent memoir* 

 on the olfactory organs of insects, from which I have 

 taken Fig. 42, representing a section through part 



Fii?. 42.— Section through part of the antenna of a wasp (after Hauser), x 430. 

 CH, Chitinous skin ; Z, olfactory cone ; G, olfactory pit ; TB, tactile hairs ; B, 

 hypodermic cells ; M, the membrane surrounding them ; K, nuclei of the olfac- 

 tory cells ; K,, remains of the earlier upper nucleus ; SK^ lower circle of rods ; 

 RS, olfactory rod ; GZ, Geisselzelle ; MZ, membrane forming cell ; Jf, membrane 

 closing the pit. 



of the antenna of a wasp, showing two of the 

 olfactory cones, one projecting beyond the general 

 surface. They terminate above in a fine rod, below in 

 a nerve-thread, and present a double series of ridges. 



* "Phys. Tind Hist. Unt. u. die Geruchsorgane der Insekten," Zeit. 

 fur Wise, Zool, 1880. 



