194 INSECT MISCELLANIES. 



low like a pipe to sucke in and convey the blood 

 through it*." 



It is not a little singular that notwithstanding the 

 early attention which was thus given to the sucker of 

 the gnat, authors are by no means agreed as to its 

 structure ; and even a recent author of talent, M. 

 Robineau Desvoidyf, has rather added to former 

 errors than contributed to expunge them. The most 

 accurate details and figures are those of Reaumur 

 and RotFredi, which we shall chiefly follow. To the 

 naked eye, the sucker of the gnat appears hke a 

 needle finer than a hair, solid and pointed ; but the 

 microscope shows that what appeared so simple, is 

 really compound and complicated. It consists, ac- 

 cording to Leeuwenhoeck of four pieces ; Swam- 

 merdam found «>, mcluding the lip ; but Reaumur 

 says there are only five. It may be that their ob- 

 servations were made upon different species, or upon 

 individuals which had sustained accidental mutilation. 

 Swammerdam, indeed, mentions that he often ob- 

 served in dead gnats the suckers broken off from their 

 case |. This case or sheath is divided in its whole 

 length, enclosing an apparatus of five piercers or 

 lancets {Scalpella), with which it cuts into the skin. 

 " After a gnat," says Reaumur, " had done me the 

 honour of settling on my hand, I perceived that it 

 put forth a very fine point from its sucker, with the 

 end of which it felt four or five spots of my skin, ap- 

 parently with the design of discovering where it could 

 obtain the most blood with the least trouble §." This 

 fine point, Swammerdam imagined to be simple and 

 indivisible, and says, " the point is so sharp that I 

 could never observe the least breadth in it with the 

 best microscopes I could procure, though if you put 

 the edges of the sharpest razors, or the points of the 



* Holland's Plinie, xi. 2. 

 t Mem. Soc. d'Hist. Nat. de Paris, iii. 390. 

 + Biblia Nat. i. 157. § Mem. iv. 583. 



