BEES PROBOSCIS 



17 



Insects, and we have omitted the term hj'poglottis altogether, 

 though some may think the mentum 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 

 applicable. 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, «) so that a 

 cup 0* cavity is formed, the 

 fluid 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 , . , „ , , j ., , 



■^ . • r, i. Fio. 9. — A, Proboscis of a " long-tougueA bee, 



the cup); it is between J KCAoyio™ ^Ji7i>e5 ,■ B, lower, C, upper view 



these two parts that the of proboscis of an "obtuse-tongued" bee, 



■■^ , , Prosopis piibescens. a, Labruni ; o, stipes ; 



fluid passes to reach the c, palpiger ; d, scale: /, lobe; g, palpus; 



pharynx. It is no doubt A, cardo, of maxilla: i.lorum; i.submentum; 



r ^ ;, meutum ; m, labial palp; ■«, paraglossa ; 



to slight movements of the «, llgula; ^, tip of Ugula (with "spoon" at tip 



1 4-„ „P <->.„ and some of the hairs more magnified) ; q, 



membranous parts ot the ,,ypopharynseal sclerites. 



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 fluid of 

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

 VOL. VI C 



