ETERNAL ANATOMY OF INSECTS. 469 



It may here be observed, that in the promuscis the 

 elongation of the organs seems to be made chiefly at the 

 expense of all the palpi, but in the proboscis at that of 

 the labial only; and in some cases at that also of the 

 mandibles or maxilla?, — the former merging in the la- 

 brum and the latter in the labium. 



iii. Antlia a . — The third kind of imperfect mouth is that 

 of the Lepidoptera, which I have called Antlia. Fabri- 

 cius denominates it lingua; but as this organ has no ana- 

 logy with the real tongue of insects, this is confessedly 

 improper, and it appeared necessary therefore to exchange 

 it for another denomination : I have endeavoured to ap- 

 ply a term to it that indicates its use — to pump up, name- 

 ly, the nectar of the flowers into the mouth of the insect. 

 On a former occasion I described to you the structure of 

 this instrument 5 ; but further discoveries with regard to 

 it having since been made by MM. Savigny and La- 

 treille, I shall here give you the result of their observa- 

 tions. The former of these able physiologists has de- 

 tected in the mouth of the Lepidoptera rudiments of al- 

 most all the parts of a perfect mouth. Of the correct- 

 ness of this assertion you may satisfy yourself, if you con- 

 sult his admirable elucidatory plates, and compare them 

 with the insects. Just above the origin of the spiral 

 tongue or pump, the head is a little prominent and 

 rounded ; and immediately below the middle of this pro- 

 minence there is a very minute, membranous, triangular 

 or semicircular piece ; which from its position, as cover- 

 ing the base of the antlia, may be regarded as the rudi- 



* Plate VI. Fig. 13. a', h' } c, d'. b Vol. I. p. 394—. 



