The Bee's Tongue 23 



This, however, does not interfere with the collecting of 

 nectar, as the tongue, or ligula {T), is covered with rows 

 of hairs which make it easy for the liquid sweets to be 

 conveyed up to the complete tube above. 



In order to examine the wonderful mechanism by which 

 the proboscis is lengthened and shortened at will, we will 

 now look at the under side of the proboscis with all the 

 parts widely separated. 



We have here the maxillcC (y^/, J/), or outer sheath, as 

 before, with both joints (i, 2) plainly distinguishable. 



Between them we have the lower lip (Z) with the upper 

 cylindrical part or mentum {Mt) and below that the two 

 labial palpi (LP, LP), these palpi forming the inner sheath. 



Between the palpi is the tongue {T) having its roots in 

 the mentum and capable of being withdrawn partly into 

 that portion, by the action of muscles joining tongue and 

 mentum. 



The maxillae are attached to a plate under the bee's 

 head at the points Z, Z, of Figs. II. and III. 



In Fig. I. these points are below and behind X, X, and 

 are concealed by the overlying parts. 



The proboscis in Fig. I. is not lowered, but is as short as 

 it can be. 



In Fig. II. the bee has lowered its proboscis by opening 

 the hinges at Z, Z, which thus lowers the point A of Fig. I. 

 to A^ of Fig. II., leaving the points of attachment, Z, Z, 

 exposed to view. 



In this way the wko/e proboscis has been lowered, the 

 inner and outer sheaths retaining their original relative 

 position to each other. 



Now the bee desires to extend its tongue still farther, 

 and to this end lowers the proboscis yet more, in order to 

 do this making use of other hinges similar to those already 

 used at Z, Z. 



