THE SPECIAL SENSES 



37 



sense of smell. These organs of taste are minute pits, 

 hairs, or short peg-like structures which form the end 

 of the gustatory nerves, and are most numerous on the 

 membranes within the mouth. They are situated at a 

 point where the food must necessarily touch them as 

 it enters the mouth and passes down the throat. 



The sense of taste is highly developed in bees. Ob- 

 servations upon the readiness with which bees use this 

 sense can be made by placing on a large platter, accessi- 

 ble to bees, plain honey and honey mixed with sub- 

 stances likely to be unpleasant to bees. Ants have 

 been drawn to honey in which there was morphine and 

 strychnine. The smell of the honey attracted them, 

 but the moment the honey touched their lips they ceased 

 eating it. Xeither in the antenna' nor anywhere out- 

 side of the month was there any organ which informed 

 them of the unpleasant substances within the honey. 

 An interesting experiment performed with wasps, was 

 as follows: sugar was fed to them from day to day 

 at a certain place, until they became accustomed to 

 coming to that place for the sugar; powdered alum was 

 substituted for the sugar. They had scarcely touched 

 it when they drew back with most comical gestures, 

 (leaning their tongues by frequently running them in 

 and out and stroking them with their fore feet. 



The Sense of Smell.- -The antenna- perform dual func- 

 tions. It has been shown in discussing the sense of 

 touch, that the antenna 1 are tactile organs. The an- 

 tenna;- may be regarded also as the principal organs of 

 smell. The nerve endings are similar to those of the 

 nerves of touch, being pits or papilla?. The sense of 

 smell is highly developed among insects. It is con- 



