

EXTERNAL ANATOMY OF INSECTS. 539 



hazard a conjecture, I should say that these organs were 

 given to this animal by an all-provident Creator, to en- 

 able it to push itself forward, when in the heart of some 

 tree it emerges from the pupa, that it may escape from 

 its confinement. Another kind of moveable appendages 

 are attached to the thorax of Lepidoptera, usually in the 

 form of a pair of concavo-convex scales covered exter- 

 nally with a tuft of hairs a . M. Chabrier, who examined 

 these scales in recent insects, describes them as vesicles, 

 which appeared to him full of a liquid and of air, and ca- 

 pable of being alternately inflated and rendered flaccid ; 

 he regards them as accessories to a pair of spiracles, 

 which he looks upon as vocal b , opening into the mani- 

 trunk just above the insertion of the arms. These or- 

 gans are quite distinct from the tegulce that cover the 

 base of the primary wings of insects of this Order c , and 

 are what, borrowing a term from Mouffet d , I have called 

 in the table patagia, or tippets. Under this head I may 

 include the caruncles at the anterior angles of the pro- 

 thorax of a genus of beetles with soft elytra, named by 

 Fabricius Malachius. When pressed, says De Geer 

 of these insects, a red inflated soft vesicle, of an irregu- 

 lar shape, and consisting of three lobes, emerges from 

 the thorax and from each side of the anterior part of the 

 abdomen, which re-enters the body when the pressure is 

 removed e . M. Latreille seems to think that these vesi- 

 cles have some analogy with the poisers of Diptera and 



1 Plate IX. Fig. 4. 



b Sur le Vol des Ins. c. vii. 374. t. xviii./. 9. i i. 



<■ Plate IX. Fig. 5. d Theatr. Ins. 98. 



,: De Geer iv. 74. 



