NO. 14 SENSE ORGANS ON MOUTH-PARTS OF BEE — McINDOO 4I 



this cavity may be stimulated by the particles touching them, thereby 

 informing the bee that the food is ready to be swallowed. The 

 presence of the food in the mouth is made known to the bee by means 

 of the hairs on the epipharynx (Ep) coming in contact with it. The 

 act of swallowing is facilitated by means of the epipharynx pushing 

 the food into the mouth. This act is explained by the fact that the 

 fleshy-like epipharynx may be moved up and down by a set of longi- 

 tudinal muscles (M 3 ), and it is also capable of completely closing the 

 mouth opening by the longitudinal (M 3 ) and transverse muscles 

 (M 10 ) working in unison. 



Should a particle of food, too large to pass through the narrow 

 oesophagus (fig. 10, E), be swallowed, it would be stopped when it 

 reached the hairs (& 3 ) on the pharnygeal plate (PhPl) by means of 

 the transverse muscles (M 10 ) contracting, thereby forcing it to the 

 exterior. It is thus seen that the hairs on the pharyngeal plate act as 

 a safety device to prevent pieces of solid food, too large to go through 

 the oesophagus, from passing into the pharynx (Ph). 



The tactile hairs on the maxillae and labial palpi are of the utmost 

 importance to workers while caring for the brood and in examining 

 the comb, etc. The hairs marked &. t on the mandibles perhaps play 

 their greatest role while these appendages are being used for building 

 comb. Regarding these as tactile hairs, it is easy to understood how 

 bees are able to mold the walls of all the cells of uniform thickness. 



6. How Bees Eat Liquid Foods 

 While watching a bee eat honey under a simple microscope, it will 

 be observed that the maxillae remain almost stationary while the 

 mentum, carrying the tongue, paraglossia and labial palpi, is being 

 moved forward and backward, up and down through the buccal cavity 

 between the maxillary bases as if the honey were being either pumped 

 or sucked up into the mouth. It is now generally believed that 

 liquid foods pass up the glossa or tongue by capillary attraction and 

 are then sucked into the mouth. This view seems to be the only 

 plausible one, and after completely understanding this method it is 

 seen that Nature could not have devised a better plan. If a bee ate 

 only liquid foods, a proboscis connecting directly with the mouth 

 would be a better apparatus, but we well know that bees eat more or 

 less of solid food in the form of pollen. 



As a typical example to serve all purposes, let us suppose that a 

 bee is about to eat candy containing a small amount of quinine, and 

 let us suppose that the bee cannot smell the quinine in the candy. 



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