Extracts from the Minute- Book of the Linnean Society. 769 
though in the case of the spiders considerable diffi- 
culties presented themselves, in consequence of the 
exceedingly minute quantity of adhesive matter emitted 
by the brushes of those animals. On submitting this 
secretion to the direct rays of the sun, in the month of 
July, and to brisk currents of air, whose drying power 
was great, I ascertained that it did not suffer any per- 
ceptible diminution by evaporation under those cir- 
cumstances. 
** Now it is reasonable to infer, from the foregoing 
researches, that the hair-like appendages constituting 
the brushes of spiders, and occurring in such profu- 
sion on the inferior surface of the pulvilli of insects, 
are tubular. ‘The delicate membrane also, on the under 
side of the prolegs, and the tarsi of the perfect legs of 
various larve capable of traversing polished perpen- 
] dicular bodies, without the aid of lines produced hy a 
spinning apparatus, must be provided with numerous 
» pores, or minute papilla, from which an adhesive se- 
cretion is emitted. Some larve which are not sup- 
plied with prolegs, those of the Coccinelle for example, 
have the inferior part of the tarsi of their perfect legs 
thickly covered with hair-like appendages resembling 
in figure, and in the function they perform, those on 
the pulvilli of insects in the imago state; while others, 
altogether destitute of legs, emit.a viscid mucus from 
both their extremities, and by advancing and attach- 
ing each alternately, are thus enabled to ascend smooth 
bodies with facility. 
** According to my observations, the instrument is 
composed of several branched membranous papille 
included in a common envelope. They are extremely 
5r2 flexible 
