44 THE ANATOMY OF THE HONEY BEE. 



food alone. By sejjarating the parts of the proboscis a little (fig. 

 !) B) it will be seen that, while there are five terminal pieces present, 

 three of them arise from one median basal sclcrite {Mt), the two 

 wider lateral appendages {Mx) being carried each by a separate lat- 

 eral basal piece {St). The median group constitutes the labium and 

 the separate lateral parts the maxillm. 



If the reader will now turn again to figure 3 C (p. 17), which may 

 rejDresent any generalized insect labium, and compare with it the 

 drawing of the bee labium, forming the median series of parts in fig. 

 15 D, he will at once be able to identify the parts of the latter. The 

 princijDal elongate median basal plate is the mentum {Mt), the small 

 triangular plate at its base is the submentum {Smt), and the two 

 jointed lateral appendages of the mentum are the labial palpi 

 {LbPlp) , each carried by a basal palpiger {Pig) ■ It is only the parts 

 of the bee's labium that lie between the paljii which are actually 

 different from those in the generalized diagiam where they consist 

 of the four lobes of the liijula {Gls and Pgl). But even here it will 

 be seen that the two small lobes {Pgl) in the bee's labium, partly con- 

 cealed within the bases of the palpi, correspond with the paraglossa. 

 Hence we have only the long median apjDendage to account for and it 

 is unquestionably the representative of the gloxficv {Gls) which are 

 here fused together and drawn out into this flexible tonguelike organ. 

 In fact, a comparison with the mouth parts of other Hymenoptera in 

 which the elements are much less modified leaves no doubt of this 

 being the true interpretation of the bee's labium. It is simjDly an 

 example of how nature constantly prefers to modify an already exist- 

 ing part to serve some new jDurpose rather than to create a new organ. 



If, then, we bear in mind that the slender median appendage of 

 the bee's labium represents the glossas of other insects, we may for 

 convenience call it the " tongue," as it is popularly termed, or, since 

 it is a single organ, there is probably no grammatical objection to 

 calling it the glossa. The word " tongue," however, to use it prop- 

 erly, should be applied to the true lingua or hypopharynx (fig. 3 C 

 and D, Hpliy) which arises fi'om the upper surface of the labium. 

 Many of the older entomologists, adopting the notion from Kirby 

 and Spence, who defined the term in 1826, regarded the glossa of 

 the bee as the homologue of the lingua in other orders. Even Pack- 

 ard in his Text-book of Entomology calls the glossa the " hypo- 

 pharynx." Cheshire named it the " ligula,'' and his mistake has been 

 perpetuated by several other writers on bee anatomy, including Cook 

 and Cowan. The term ligvla properly includes both the glossa and 

 the paraglossa^ or should signify the basal piece from which these 

 four lobes arise (fig. 3 C, Lg), so that it can not be applied to the 

 o-lossa alone. 



