266 ON AERONAUTIC SPIDERS. 
motivement.” In this bold but fanciful conjecture, 
M. Virey has been anticipated by our celebrated 
countryman Dr. Lister, who, in treating upon his 
“araneus subfuscus, minutissimis oculis é viola pur- 
purascentibus, tardipes, & gressu & figura cancro 
marino non adeo dissimilis,” remarks, “certé egre- 
gius funambulus est, & mirificé filorum ejaculatione 
delectatur : neque soltim in aére, uti superiores, vehi- 
tur; sed ipse etiam ascensum velificationémque moli- 
tur, pedibus scilicet arctitis ad se invicem applicitis 
sese quodammodo librat, cursum promovet regitque 
nihilo secitis quam si illi essent 4 natura concesse 
ale vel remorum ordines”*. Supported by such 
high authorities as these, this hypothesis assumes an 
air of importance to which it is not otherwise en- 
titled, since the single fact that spiders, when sail- 
ing in the atmosphere, invariably fall to the ground 
on being separated from their lines, is alone sufficient 
to effect its complete subversion. Moreover, I have 
thoroughly satisfied myself, by much elaborate inves- 
tigation, that spiders never ascend into the air spon- 
taneously without the assistance of lines connected 
with the spinners, and that when they perform their 
aérial journeys their legs are usually in a state of 
quiescence, being contracted and brought into close 
contaet with the body: indeed, should the limbs 
happen to be observed in motion, they will generally 
be found, on minute inspection, to be employed in 
* «De Araneis,’ p. 85. 
