THE ALIMENTARY CANAL AND ITS GLANDS. 91 



dorsally to above the antennae, where it turns posteriorly and con- 

 tracts into the much narrower oesophagus (CE). Attached to its 

 walls are numerous suspensorial muscles, whose contraction must 

 expand the pharyngeal cavity, while the latter may be contracted 

 by the sheet of muscles surrounding its walls. In this way the 

 pharynx is undoubtedly able to perform a sucking action, by means 

 of which the liquid foods are taken into the mouth. Its lateral 

 walls are strengthened by two long, chitinous rods (figs. 11 B and 

 19, A) , which arise from a median anterior plate in its floor (fig. 19, s) . 

 The anterior end of this plate is prolonged into two free, tapering 

 lobes which hang down over the lower rim of the mouth. The plate, 

 in the worker, and the bases of the rods are shown in ventral view, 

 removed from the pharyngeal wall, in figure 43 D. Near where the 

 rods join the plate are two long, chitinous pockets (mm), opening 

 above, which receive the ducts of the two large glands (JGl) lying 

 within the anterior part of the head. Between these two pockets is a 

 transverse row of cells (4(^1), which have been described by Bordas 

 (1895) as the " sublingual glands," but this name is not appropriate 

 in insects, for, while the gland in question may be suggestive of the 

 sublingual salivary gland of vertebrates, it does not lie beneath the 

 tongue or lingua of the bee. Although the pharyngeal plate lies 

 upon the floor of the true mouth, it is not, as already explained (p. 

 44) , the equivalent of what is properly called the tongue, lingua, or 

 hypopharynx in other insects — this organ being absent in most 

 Hymenoptera. The only suggestion the writer can make, however, 

 is to call this group of cells the ventral or median ventral pharyngeal 

 gland in distinction to the large lateral glands. A comparative view 

 of the pharyngeal plate and its accessory parts in the drone is given 

 in figure 43 E. The plate itself (s) is shorter than in the worker, 

 and its anterior lobes are smaller. The lateral glands and their 

 receptacula are entirely absent, but the median glands (4<?0~.are 

 much larger than those of the worker. Bordas says that each acinus 

 of the latter glands in both the worker and the drone is provided 

 with a fine, sinuous canaliculus, and that these tiny ducts open 

 separately in two bundles on the lateral parts of the pharyngeal 

 plate. The' lateral glands are present in the queen, but are very small 

 and rudimentary. 



Especial interest attaches to the large lateral pharyngeal glands of 

 the worker {System No. 1 of Cheshire, the sufracerehral glands 

 of Bordas) , because they are regarded by many as the source of the 

 brood food and the so-called " royal jelly," which is fed to the larvae 

 and to the adult queens and drones by the workers. Each consists 

 of a long coiled string of small ovate follicles attached to one median 

 duct (fig. 43 A) and the two are intricately packed into the anterior 

 and upper parts of the head (figs. 10 A, 19, and 42, IGl). Each 



