SLIME SLUGS, MYRIAPODS AND INSECTS 129 



hairy rod is forced up the tube by the pressing together of the 

 parts composing its walls. 



Antennae and Senses. The two feelers, or antennae, of the 

 bee are slender, elbowed processes, each composed of thirteen 

 small segments, which can be moved freely, and extend out in 

 front of the face so as to be in advance of the head when the 

 bee is flying or walking. They are general 

 organs of touch and smell and probably 

 also of hearing. Each of these senses 

 has its own particular specific organs on 

 the antennae, those of feeling being fine 

 tactile hairs and papillae, those of smell 

 being variously shaped very minute pits 

 or cones, each with a fine nerve ending 

 in it, while those of hearing are more 

 problematical. But it has been proved 

 that many insects have special auditory 

 organs in the antennae consisting usually 

 of fine hairs which can be set into vib- 

 ration by the sound waves, and an elabo- 

 rate receiving arrangement, in the second FlG 5 x Mouth- 

 segment, of chitin rods, delicate nerve parts of a honey-bee 



fibers, special ganglion cells and an audi- with maxilla and man- 



. . , i rr^i dibles of one side re- 



tory nerve running to the brain. The moved . md ^ mam li- 



male mosquito has a very highly deve- ble; mx., maxilla; mx.p. 



loped auditory apparatus of this type. maxillary palpus; mx.l 



J , f maxillary lobe; si. 



A few insects, such as the grasshopper, st i pes O f maxilla; cd. 



katydids, crickets and others have a cardo of maxilla; //. 

 very different kind of "ear," not situated . 



on the head, but on the abdomen (in mentumof labium; pg. 

 the grasshoppers), front legs (in katydids paraglossa. g/., glossa 



1. ^t u j lip-, labia palpus, 



and crickets), or elsewhere on the body. 



This kind of ear is composed of a small, thin vibratory drum 

 or tympanum, with an air-space underneath it, and a tiny 

 ganglion and special nerve in connection with it. 



The sense of smell is very highly developed in most insects. 

 Indeed it is probable that most of an insect's sensation of out- 

 side things comes through its organs of smell. And the 



