THE HEAD OF THE BEE AND ITS APPENDAGES. 49 



The entire ventral cavity (Lum) with the rod (r) can be evaginated 

 through the ventral cleft (k) by blood pressure from within. At 

 Cheshire points out, this permits of the channels being cleaned in 

 case of clogging by pollen or any foreign matter. 



It is supposed that these glossal tubes are of especial service to the 

 bee by enabling it to take up the smallest drops of nectar- -quantities 

 that would be lost in the clumsy tube formed between the parts of 

 the Jabium and the maxillae. The suction must be in large part 

 capillary attraction, but here again the shortening of the glossa by 

 the retraction of its rod must squeeze the contained nectar out of the 

 upper ends of the channels where it is received upon the ventral flaps 

 of the paraglossa3 (fig. 15 F, Pffl), from which it runs around the 

 base of the tongue (Gls) within the paraglossaj to the dorsal side of 

 the mentum (Mt) and so on to the mouth. 



The maxillae and labium of both the queen and the drone (fig. 11 

 B) are smaller and weaker than those of the worker, and neither of 

 these two forms is capable of feeding itself to any extent. If a 

 hungry queen be given some honey she attempts to eat it and does 

 imbibe a small quantity, but at the same time she gets it very much 

 smeared over her head and thorax. 



The mouth is hard to define in insects; practically it is the space 

 surrounded by the bases of the mouth parts, but strictly speaking it 

 is the anterior opening of the alimentary canal situated behind the 

 bases of the mouth parts (fig. 19, Mth). Yet the enlargement of the 

 alimentary canal (Phy) immediately following this opening is never 

 spoken of as the mouth cavity but is called the pharynx. On the 

 other hand the so-called epipharynx {Ephy) and hypopharynx 

 (absent in the bee) are located in front of this opening and are con- 

 sequently not in the pharynx at all, the former being attached to the 

 under surface of the labrum and clypeus, while the latter is situated 

 on the upper surface of the base of the labium. These and numerous 

 other inconsistencies in the nomenclature of insect morphology have 

 to be endured because the parts were originally named for descrip- 

 tive purposes by entomologists who were not familiar with scientific 

 anatomy. In this paper the term mouth will be applied to the true 

 oral opening (fig. 19, Mth). The space in front of it between the 

 bases of the mouth parts may be called the freoral cavity. 



The duct of the salivary glands of insects in general opens upon the 

 base of the labium in front of the hypopharynx. In the honey bee 

 the salivary opening is on the dorsal side of the base of the ligula 

 between the paraglossse (fig. 15 F, SalDO). This alone would show 

 that the glossa is not the hypopharynx of the bee, as many authors 

 have supposed, for otherwise the opening of the salivary duct should 

 be ventrad to the base of the glossa. In fact, this makes it clear that 

 22181— No. 18—10 4 



