6 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. IO3 



the approximated parts. The pointed ends of the galeae converge 

 over the protruding distal part of the tongue (fig. 3C), but the 

 small terminal segments of the labial palpi diverge laterally beyond 

 the galeae and serve as sensory outposts. Back-and-forth movements 

 of the tongue draw the food liquid into the canal of the proboscis, 

 through which it ascends probably at first by capillary attraction, but 

 before reaching the mouth the liquid is received into a preoral food 

 channel on the base of the labium (fig. 9 A) between the bases of 

 the maxillae, closed anteriorly by the epipharynx (B). Here at 

 least the action of the sucking pump must become efifective in finally 

 drawing the liquid food into the mouth. 



The proboscis as a whole is retractile and protractile by swinging 

 back and forth on the long, suspensory rodlike cardines of the maxillae 

 (figs. 3 A, 4 A, Cd), which are hinged to the sides of the cavity on 

 the back of the head that lodges the bases of the maxillae and labium, 

 but the tongue and the paraglossae themselves are deeply retractile 

 into the end of the basal part of the labium (fig. 7 D, E). 



The sucking pump of the aculeate Hymenoptera lies entirely within 

 the head (fig. 10 A), and is clearly a combination of structures that 

 in generalized insects constitute two distinct regions of the alimentary 

 tract. The first is the true pumping apparatus (Cb) ; it is derived 

 from the cibarial chamber of the preoral "mouth cavity," which 

 primitively is a food pocket between the epipharyngeal wall of the 

 clypeus and the base of the hypopharynx that is distensible by 

 dilator muscles arising on the clypeus. The second part (Phy) 

 represents the usual postoral pharyngeal dilatation of the stomodaeum. 

 In the bee, as in most other sucking insects, the cibarial chamber has 

 been enclosed within the head and converted into a sucking mecha- 

 nism ; but, while in Hemiptera and Diptera the pump is entirely a 

 cibarial structure, in the Hymenoptera and Lepidoptera the cibarium 

 and the pharynx are united to form a single pumping organ, in 

 which, however, the cibarial and pharyngeal components may be 

 identified. With the worker bee egestion is an important function 

 of the feeding apparatus in the preparation of honey from nectar 

 and in the feeding of the brood, the queen, and the drones ; it is 

 probable, therefore, that the sucking pump is also the principal 

 regurgitative organ. 



The salivary ejection apparatus of the bee is merely the salivary 

 pocket, or salivarium, between the base of the hypopharynx and 

 the base of the labium, into which commonly opens the salivary duct. 

 The salivarium is converted into a closed chamber by the union of 

 the hypopharynx with the anterior wall of the labium, and its 



