TEE SENSES OF INSECTS. 



about 70 tactile hairs; on the terminal joint there are 

 more than 200 teeth, so that each antenna has between 

 13,000 and 14,000 olfactory pits and about 700 teeth, 

 at 



n t 



FIG. 20 Organs of smell in Melolontha. n, olfactory or antennal nerve; sc. gan- 

 glion-cells from which a thread-like fibre is sent to each pit (p), ending in a 

 hair or style (st)\ m, olfactory membrane. After Eraepelin. 



Similar pits occur in the long, jointed anal stylets of the 

 cockroach, and in those of certain flies (Ohrysopila). 



Plateau, as well as Will and Forel, deny that the palpi 

 have the sense of taste, but maintain that they are simply 

 organs of touch; Forel appears 

 to have experimentally proved 

 this by cutting off the palpi 

 of wasps and ants, and feed- 

 ing them with meal with which 

 quinine and morphine had FlG 21 _ 4 6 sense . orj?ans on the ab . 



>>ocm liv^rl wViir-Ti tlipv <?till dominal appendages of a fly (Chry- 

 been mixed, Wll ley SI sopila); c, a similar pit in last joint 



rejected, though they would of palpus of Peria. 



eat pure, unadulterated meal. Yet in the end of the palpi 



of Perla we have found a sense-pit (Fig. 21, c). 



Little is positively known of the organs of taste, but the 

 researches of F. Will show that wasps and bees are provided 

 either with microscopic pits or goblet-like projections on the 

 base of the ligula (which forms the end of the under lip), 

 as well as on the- under side of the maxillae. The gustatory 



