4GS EXTERNAL ANATOMY OF INSECTS. 



served there appear to he Jive, one of which, as slender 

 as a hair, I regard as the analogue of the tongue a . — 

 When the lancets are reduced to two, they probably re- 

 present the maxilla?, the mandibles being absorbed in 

 the labrum ,■ and where there is only one, the maxillee 

 also are absorbed by the labium, which then bears the 

 palpi, the lancet representing the tongue b . The lancets 

 are so constructed in many cases, as to be able by their 

 union to form a tube proper for suction, or rather for 

 forcing the fluid by the pressure of the lower parts to the 

 pharynx c . Labial palpi appear not usually present in 

 the proboscis ; but M. Savigny thinks he has discovered 

 vestiges of them in Tabanus d . In this genus the maxil- 

 lary ones are large, and consist of two joints e . The pro- 

 boscis is often so folded, as to form two elbows; the base 

 forming an angle with the stalk, and the latter with the 

 lips, so as in shape to represent the letter Z, only that the 

 upper angle points to the breast, and the lower one to 

 the mouth : this is the case with the flesh-fly and many 

 others. In other flies, as Conops and Stomoxys, whose 

 punctures on our legs so torment us f , there is only a 

 single fold, with its angle to the breast. The proboscis is 

 received in a large oblong cavity of the underside of the 

 anterior part of the head. 



a Plate VII. Fjg. 5. This figure is copied from Reaumur, and 

 was engraved before this discovery was made. 



b M. Savigny is of opinion that the central lancet or lancets re- 

 present the Epipharynx and Hypopharynx ; for which he does not 

 state his reasons : but as these are properly covers of the pharynx, 

 the idea seems incorrect. Ubi supr. 15. 



c N. Diet. a" Hist. Nat. ix. 489. and iv. 253—. 



d Ubi supr. 36. « Ibid. t. iv./. 1. o. o. 



f Vol. I. p. 48, 110—. 



