NO. 14 SENSE ORGANS ON MOUTH-PARTS OF BEE — McINDOO 49 



Becker (1882) found sense hairs on the ventral side of the labrum 

 of certain Diptera. He believed that they serve as gustatory organs. 



Haller (1882) says that the small hairs and pegs on the dorsal side 

 of the labium of Hydrodroma rubra probably serve as gustatory 

 organs. 



Kraepelin ( 1882, 1883) attributes a gustatory or olfactory function 

 to certain innervated hairs on the proboscides of Hymenoptera and 

 Diptera. 



Kirbach (1883) calls certain small hairs in Lepidoptera gustatory 

 papillae. 



Briant (1884) regards the innervated hairs on the tongue of the bee 

 as merely tactile organs and not as gustatory structures as generally 

 believed. 



Sommer (1885) found innervated hairs on the legs, palpi, labrum 

 and labium of Macrotoma plumbea (Thysanura), but he says 

 nothing about their function. 



Will (1885) gives a drawing of a hair from the tip of the tongue 

 of Vespa, but none from Apis nor Bombus. The sense cell is multi- 

 nucleated, and the sense fiber stops in the base of the hair, whose walls 

 are thick. 



Breithaupt (1886) described papillae with very short hairs on the 

 mouth-parts of Bombus. He thinks that some serve as gustatory 

 organs while others serve as tactile organs, the function being deter- 

 mined by the location of the hairs. 



Gazagnaire (1886) says that the gustatory organs in Coleoptera 

 should be found in the buccal cavity in the form of hairs. 



Vom Rath (1887, 1888, 1894, 1896) has made a comprehensive 

 study of the morphology of all kinds of hairs on the mouth-parts 

 belonging to various insect orders. All his drawings are good, and 

 each sense hair, peg or cone is usually innervated with a sense cell 

 group, but sometimes with a single sense cell. 



Reuter (1888) describes cone-shaped sense hairs on the palpi of 

 Lepidoptera. These are connected with sense cell groups. 



Packard (1889, 1903) studied the epipharynx in various insect 

 orders. He almost invariably found hairlike sense organs on each 

 epipharynx examined. These organs are setae associated with sense 

 pits, cups and rods. Packard seems to think that some of the setae 

 are used merely to guard the sense cups while the others aid the sense 

 cups in receiving gustatory stimuli. 



Nagel (1892, 1894, 1897) has made a special study of the mor- 

 phology of the olfactory and gustatory organs of insects. He divides 



