OLFACTORY SENSE OF THE HONEY BEE 333 



The sense fiber of the sense cell pierces the bottom of this cone 

 and enters the round, oblong, or slitlike external chitinous pore 

 aperture. The morphology of the pores and the sense cells 

 in the wings, legs, and stings is identical, with the exception 

 of variations in size and shape. The complete innervation for 

 those in the wings and legs is also identical. The interior of 

 the base of the wings is literally a solid mass of sense cells while 

 in the legs and stings these cells occupy comparatively little 

 space. In the worker bee the pores and sense cells are first noticed 

 in the 17-day-old pupa, and the sense cells do not reach their 

 full size until the bee arrives at the adult stage, although all the 

 pores seem to be present in the 19-day-old pupa. 



Judging from the structure of these organs it is observed that 

 the cytoplasm in the end of the sense fiber just beneath the pore 

 aperture is constantly in contact with the external air. In spec- 

 ulating as to the function of such an apparatus, all mechanical 

 senses, such as sight, touch, and hearing, must be excluded, and 

 these organs may be presumed to react to some kind of a chemical 

 stimulus, as humidity, temperature, taste, or smell. Without 

 hesitation taste may be excluded, for the food of a bee never 

 comes in contact with the parts containing these pores. 



PHYSIOLOGY OF OLFACTORY PORES 



To ascertain whether the pores which have been studied are 

 actually the organs in the bee that receive odor stimuli, the wings, 

 legs, and stings of many workers were operated upon. The 

 behavior of these individuals was carefully studied and they 

 were tested with various odors as described on page 280. 



TVings cut off 



All four wings of 50 middle-aged workers were cut off close 

 to the thorax with small dissecting scissors. An examination of 

 these wings showed that only occasionally did the scissors pass 

 through a group of these pores. These bees were entirely nor- 

 mal, judging by their behavior and longevity. They lived from 

 IS hours to 16 days, with 9 days and 23 hours as an average. 



