FLYING SPIDERS. 149 
atmosphere depends entirely upon currents of air acting upon 
their bodies. or upon threads of cobweb attached to them. By 
this means they are blown about like the down of thistles or any 
light objects, rising sometimes to a great height and again, upon a 
change of weather, falling, often far from the place whence they 
rose. 
In the autumn of 1870 I received a letter from an officer on one 
of the United States vessels, in which he stated that one day 
while at anchor near Montevideo, after a strong wind, the rigging 
was filled with cobwebs, and little niente dropped down on all 
parts of the deck. 
Mr. Darwin, when in the same region during the voyage of the 
Beagle, several times noticed the same occurrence. He says in 
his narrative of that voyage :* — 
“On several occasions, when the vessel has been within the 
mouth of the Plata, the rigging has been coated with the web of 
he gossamer spider. One day (November Ist, 1832) I paid par- 
ticular attention to the phenomenon. The weather had been fine 
to be produc ced by the entanglement of the single threads. The 
spiders — all of one species, but of both a together with 
VOCE ODOR) 465.6: e ede 3 While watching s e that were sus- 
pended oe a single thread, I several A ae pera that the 
Hn gee miy of air bore them away out of sight, in a horizon- 
tal line. On another occasion (Nov. 25th) under similar circum- 
PER I teeters observed the same kind of small — 
ce 
lateral course, but with a rapidity that was quite unaccountable. 
I thonght I gona perceive that the spider, before performing the 
tory steps, connected its legs together with the most 
: pant, Gras but I am not sure whether this observation is 
m “One day at Santa Fé I had a better opportuni 
similar facts. A spider, which was about three-tenths of an inch 
* Journal of the Voyage of the Beagle, p. 187. 
