AUDITORY SENSE OF HONEY-BEE 189 



probably be more correct by classifying them as tactile organs 

 rather than as auditory perceptors. 



c. Structure of other antennal organs. Relative to the other 

 antennal organs, there are four, all of which are really hairs. 

 The tactile hairs (fig. 13, THr) or sensilla trichodea are scarce 

 on the antennae of the male honey-bees, but numerous on the 

 antennae of the females. They are regarded by all the observers 

 as tactile organs. The pegs {Pg) or sensilla basiconica are absent 

 in the males, but numerous on the antennae of the females. They 

 are generally considered as olfactory organs, because their tips 

 are covered with very thin chitin. The present writer believes 

 that they are very delicate touch organs. 



The pit pegs (fig. 13, PP) or sensilla coeloconica and Forel 

 flasks (Fl) or sensilla ampuUacea are hairs inside of pits. On the 

 antennae of the males both of these types are somewhat numer- 

 ous, but on the antennae of the females they are comparatively 

 scarce. Viewed superficially, one type cannot be distinguished 

 from the other, but sections show that the pit pegs are usually 

 the larger in diameter. Relative to the antennae of workers, 

 most of these organs (fig. 3, PP and Fl) lie in groups on the 

 sixth to twelfth segments, and counting both types combined 

 there are not more than 100 individual organs on each antenna. 

 In regard to their internal structure, they differ somewhat, as 

 may be seen by referring to figures 10, 11, and 13. In both types 

 the semitransparent hair (Hr) ends in a cavity (Co), which com- 

 municates with the exterior by a minute aperture (Ap), and each 

 hair is connected with a nerve strand (St), which runs to a sense 

 cell group (SCG). The function of these organs is usually 

 regarded as problematical, but still a few authors have called 

 them auditory organs. The present writer has no conception 

 of what their function is, but for some time he has looked upon 

 them as more or less degenerated structures. 



At this place the writer wishes to call attention to an erroneous 

 idea which text-book writers still persist in handing down. Be- 

 fore understanding the internal anatomy of antennae, some of the 

 early microscopists imagined that they saw gland cells among the 

 masses of sense-cell groups. This led to the idea that in order 



