478 ANNUAL, REPORT SMITHSONIAN INSTITUTION, 1020. 



<? 16 ), have been called taste hairs by other authors. While eating 

 solid food the fleshy epipharynx, suspended at the roof of the mouth 

 cavity, acts like a real tongue by feeling the food and pushing it into 

 the mouth opening, where it then comes in contact with the sense 

 hairs at the entrance of the pharynx, which act as a safety device to 

 prevent pieces of solid food, too large to go through the esophagus, 

 from passing into the pharynx. 



A person often wonders how bees, since they are covered with a 

 hard integument, are able to perform their many duties of caring for 

 the brood, building comb, etc., but it seems obvious that they first 

 examine objects with the tips of their antennae which are covered 

 with the peglike tactile hairs, then the jaws (fig. 9, Md) seize the 

 object and handle it so skillfully that it really appears marvelous. 

 All of these activities are accomplished by many tactile hairs on the 

 various appendages, but particularly by the row of curved hairs 

 (fig. 9, h i and fig. 13) at the tip of the jaws, which act like tiny 

 fingers, although perhaps a hundred times more sensitive than our 

 fingers. These hairs are able to perceive the size, shape, and firmness 

 of any small solid object, and now it is easy to understand how bees 

 are able to mold the walls of all their cells of uniform thickness. 



THE SENSE OF HEARING. 



Concerning the special senses of insects, the sense of hearing is 

 perhaps the least understood ; but according to the earliest writers on 

 this subject, this sense would seem to be highly developed in spiders 

 and insects, because we are told that some species not only make 

 musical sounds, but also are great lovers of music. This is particu- 

 larly claimed for spiders, but not one iota of truth can be accredited 

 to certain old romantic stories in which the hero, confined in a dun- 

 geon, charmed spiders with sweet music and prognosticated the 

 weather by observing their behavior. According to the latest experi- 

 mental results, spiders are not only deaf, but also most of them are 

 dumb, only a few being able to make sounds. 



Much has been written about the auditory sense of insects, but 

 critics still contend that it has never been demonstrated beyond a 

 doubt that any insect can really hear; nevertheless, we should not 

 expect insects to respond to sounds which have no significance to 

 them, nor to sounds not in their category, because they may not hear 

 the sounds that we do. The number of vibrations perceptible to the 

 human ear varies from 16 to 60,000 per second, but most human ears 

 can not hear when the frequency is lower than 32 vibrations per 

 second. Now, it may be that the insect ear is so poorly developed 

 that it can hear only sounds having vibrations below 32 per second. 



It is generally believed that insects can hear, for three reasons, 

 as follows: (1) Many have special sound-producing organs; (2) 



