rNTRODUCTION. 
85 
pour ainsi dire, I’insecte I’applique contre la feuille, 
il est asses gluant pour s'y coUer : il peut Men ayoir 
ete tire di oit d’une paxtie de la feuille a I’autre, mais 
il ne S 9 aui-oit ayoir ete ass& tendu pour faire un 
effort capaMe de ramener une des deux parties de 
la feuille yers I’autre. Je S 9 ais que ce fil, quoique 
extremement delie, a quelque force ; je lai yu en 
Men de circonstances, suspendre la chenille en fair, 
mais il n’a pas ete possible, que quand il a ete attache 
ayec le degre de tension necessaire pour forcer une 
des parties d'une feuille a’ s'approcher de I’autre. 
Si apres ayoir A6 file, il se raccourcissoit en se'chant, 
ce raccourcissement le mettroit en etat d’agir; 
mais ou peut aller le raccourcissement d’un fil si 
court ? Comhien seroit petite la courhure qu’il 
pourrait donncr a la feuille* 1” It is yeiy likely, 
howeyer, that the thread sufiers some contraction as 
the moisture eyaporates by the action of the air, and 
howeyer slight that contraction may he, that it co- 
operates with other causes to produce the curyature. 
The only other means which the insect has been 
obseryed to employ, are draudng the threads towards 
itself by its fore legs, and hanging upon them with 
the whole weight of its hod 3 \ These threads are not 
placed at random, but arranged in small bundles or 
fascicles, each of which consists of two parallel rows, 
crossing each other in the centre. "When the insect 
has formed the lower series, it passes to.the other side 
and spins the second, making use of the former, while 
so doing, as a kind of platform for the support of its 
* Kcaumur, Mem. ii. p. 215* 
