CH. XVI.] DIPTEROUS INSECTS. 



239 



consists of only four pieces, while Reaumur found 

 five, and Swammerdam six, including the lower lip, 



in which they are enclosed as in a canal. We have, 

 however, found seven pieces ; namely, the lower 

 and upper lips, the tongue, and two lancet-like man- 

 dibles, and the same number of maxillae, being of 

 equal length with the latter. The same number of 

 organs (exclusive of the pair of hairy palpi) is also 

 found in the Tabani. 



Another circumstance in which both the gnats 

 and Tabani agree is, that the females alone appear 

 to possess these sanguinary propensities, the males 

 contenting themselves with the nectar of flowers; 



