EXTERNAL ANATOMY OF INSECTS. 467 
tongue *.— When the lancets are reduced to two, they 
probably represent the mazilla, the mandibles being ab- 
sorbed in the Jabrum; and where there is only one, the 
maxillz also are absorbed by the Jabiam, which then 
bears the palpi, the lancet representing the tongue °. 
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’. Labial palpi appear not usually 
present in the proboscis; but M. Savigny thinks he has 
discovered vestiges of them in Zabanus*. In this genus 
the maxillary ones are large, and consist of wo joints *. 
The proboscis 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 Sto- 
moxys, whose punctures on our legs so torment us ‘, there 
is only a single fold, with its angle to the breast. ‘The 
proboscis is received ina large oblong cavity of the under- 
side of the anterior part of the head. 
It may here be observed, that in the promuscis the 
elongation of the organs seems to be made chiefly at the 
* Prats VII. Fic. 5. This figure is copied from Reaumur, and 
was engraved before this discovery was made. 
> 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. 
° WN. Dict. d’Hist. Nat. ix. 489. and iv. 253—. 
4 Ubi supr. 36. © Ibid. ¢. iv. f. 1. 0. 0, 
‘ Vor. I. p. 48, 110—, 
9u@2 
