LEPIDOPTEEA. 175 



This trunk, of which the butterfly makes such good use, is 

 composed of two fillets more or less long, horny, concave in their 

 interior surfaces, and fastened together by 

 their edges. When cut transversely, one 

 sees, according to Eeaumur,* that the in- 

 terior is composed of three small rings. 

 Consequently, there are three canals in the 

 trunk, one central, the other two lateral 

 (Fig. 138). Are all these three used to con- 

 duct the juice of flowers into the butterfly's 

 body ? Eeaumur has made some very in- 

 teresting observations on this subject, by 

 observing a moth which was sucking a lump Fig " 

 of sugar, whilst its portrait was being taken. 



"I held in one hand," says Eeaumur, "a powerful magnifying 

 glass, which I brought near to that part of the trunk I wished to 

 examine ; I was sometimes half a minute, or nearly a minute, 

 without perceiving anything, after which I saw clearly a little 

 column of liquid mounting quickly along the whole length of the 

 trunk. Often this column appeared to be intersected by little 

 balls which seemed to be globules of air which had been drawn up 

 with the liquid. This liquid ascended thus during three or four 

 seconds, and then ceased. At the end of an interval of a greater 

 number of seconds, or sometimes after an interval as short, I saw 

 some fresh liquid mounting up along the trunk. But it was straight 

 up the middle of the trunk that it seemed to ascend. 



" The Author of nature has given to insects means of working, 

 which, though very simple, we cannot divine, and which often 

 we are not able even to perceive. Whilst I was observing the 

 trunk of our butterfly, between the columns of liquid which I saw 

 ascending, there were, but more rarely, times when I saw, on the 

 contrary, liquid descending from the base of the trunk to the point. 

 The descending liquid occupied half or two- thirds of the tube. It 

 was no longer difficult to perceive how the butterfly is able to 

 nourish itself on honey, the thickest syrup, and even the most 

 solid sugar. The fluid it sends down is apparently very liquid ; 

 it drives against the sugar, moistens, and dissolves it. The 



* Planche 9, Fig. 10, oe memoire, " Sur les parties exterieurs des papillons." 



