38 THE ANATOMY OF THE HONEY BEE. 



As before stated, it has been conclusively proved by several investi- 

 gators that bees perceive odors, and it is said that if the antennae 

 are covered with shellac, bees can distinguish between distasteful 

 substances only by means of the proboscis. Schiemenz and most 

 other writers on the subject therefore conclude that the sunken cones 

 are the organs of smell, since, being below the surface, they could not 

 be organs of touch. Some other authors, however, among whom are 

 Cheshire, regard these inclosed cones as hearing organs. They sup- 

 pose that the sound waves of the air enter the pit, as into an ear 

 cavity, and these set up a vibration in the cone which stimulates the 

 attached nerve ending. However, the appearance of one of these 

 cones would suggest that it is too stable a structure to be affected 

 by sound waves, so the olfactory theory seems much more probable. 



Finally, Schiemenz describes the most specialized of all the anten- 

 nal sense organs as a closed cavity {Pt) in the cuticle {Ctl) extend- 

 ing into the hollow of the antenna as a long, curved, tapering sac. 

 This is shown at F of figure 12. A nerve {Nv) enters the lower 

 extremity of the pouch, expands slightly into a nucleated ganglion 

 cell {CI), and then extends toward the top as a delicate spindle 

 drawn out into a fine tapering point. The surface covering of the 

 pit is a thin layer of chitin presenting several concentric light and 

 dark rings surrounding a central disc {hr). Sections show that this 

 appearance of rings is due to circular thickenings of the membrane, 

 and Schiemenz points out that the central disc is probably a modi- 

 fied hair, while the whole structure is to be regarded simply as a 

 modification of a tactile organ such as that shown at D with the 

 nerve- ending and its ganglion inclosed in a sac. These organs are 

 most abundant on the antennae of the drones, where they are situ- 

 ated, especially on the under surface, so close together that but little 

 space is left between them for the tactile hairs, while in the workers 

 and queens they are farther apart and are interspaced with many 

 tactile hairs. Hence, whatever sense they accommodate must be 

 much more highly developed in the males than in the females. 

 Schiemenz described these organs, as well as the sunken cones, as 

 organs of smell. He ascribed only the senses of touch and smell to 

 the antennae, and both Cheshire and Cowan concur in his view of the 

 closed pits. Arnhart (1906), however, argues that an organ of smell 

 must be open to the air in order to permit the ingress of odor par- 

 ticles. Such an organ is constituted by the sunken cones, but the 

 closed pits have nothing to recommend them for an olfactory func- 

 tion. Arnhart then further points out that the buried sacs, inclosing 

 a delicately poised nerve-ending and covered by an external tym- 

 panum, have all the mechanical elements of an organ of hearing. 

 He finally argues that bees must hear, since they produce special 

 sounds such as the piping of the queens, and that, since no possible 



