THE SENSES OF INSECTS — McINDOO. 



471 



stance or many of them totally destroyed by removing the wings. 

 After the mutilated insects had apparently recovered from the oper- 

 ations, they were again tested with the same sources of odors. Those 

 ants, bees, and hornets with mutilated antennae usually failed to re- 

 spond to odors, but they were very abnormal, soon became sick and 

 never lived long. Those beetles, grasshoppers, and crickets with 

 mutilated antennae usually responded to odors and lived practically 

 as long as others not mutilated. All of those insects with destroyed 



Pigs. 6 to 8. — Olfactory organs of insects. Fig. G, section of olfactory pore 

 in leg of worker honeybee, showing nerve (N) passing to exterior through 

 aperture in " skin " or chitin (Ch) ; enlarged GOO times. Fig. 7, external 

 view of four types of olfactory pores (Nos. 14-16 and f) on halter (rudi- 

 mentary hind wing) of house fly ; enlarged 500 times. Fig. 8, schematic 

 drawing of a portion of a row from group No. 14, showing the remark- 

 able architecture of these organs in perspective and in section. 



or covered olfactory pores responded to odors more slowly then be- 

 fore being mutilated, and the degree of slowness depended on the 

 number of pores prevented from functioning. All of these insects 

 were apparently normal in other ways and lived practically as long as 

 intact ones. 



The question has often been raised as to how certain female 

 moths are able to attract males from miles away. Mayer attempted 



