11KKS PKOISOSCIS 



Insects, ami we have omitted the term liypoglott is altogether. 

 though some may think the mentmn entitled to that name. 



The way in which the proboscis of the bee acts has been very 

 largely discussed, with 



special reference to the ^ -^ 



question as to whether it is 

 a sucking or a licking action. 

 It is impossible to consider 

 either of these terms as 

 iijiplicable. The foundation 

 of the action is capillary 

 attraction, by which, and by 

 slight movements of increase 

 and contraction of the 

 capacity of various parts, the 

 fluid travels to the cavity 

 in front of the hypopharynx : 

 here the scales of the 

 maxillae leave a vacant 

 space, (Fig. 7, e) so that a 

 cup or cavity is formed, the 

 ihiid in which is within 

 reach of the tip of the depen- 

 dent epipharynx (c), which 

 hangs down over the front 

 of the hypopharynx (and is 

 so shaped that its tip covers 

 the cup) ; it is between 

 these two parts that the 

 fluid passes to reach the 

 pharynx. It is no doubt 

 to slight movements of the 

 membranous parts of the 

 hypopharynx and of the 

 epipharynx that the further progress of the nectar is due, aided 

 by contraction and expansion of the pharynx, induced by muscles 

 attached to it. It should be recollected that in addition to the 

 movements of the head itself, the hypopharynx is constantly 

 changing its dimensions slightly by the impulses of the lluid of 

 the general body cavity; also that the head changes its position, 



VOL. VI C 



9 



a- 



FIG. 9. A, Proboscis of a "long-tongued" bee, 

 .1 iitli'ijilmri/ jiili/iss ; B, lower, C, upper view 

 of proboscis of au " obtuse-tongued " bee, 

 /';, .vy ( /s- finln'fti-i-ns. , Labruni ; />, stiprs : 

 r, pulpuier ; rl, scale : /', Inbe ; ,'/, pa' pus : 

 //. rardo, of maxilla : i', lorum ; /.', submentum : 

 /. meutum ; m, labial palp; n, parnirlossa ; 

 ". liuula; j>. tip of ligula (with "spoon " at tip 

 and some of the hairs more magnified) ; /. 

 hypopharyngeal sclerites. 



