THE ARACHNIDA. 303 
the rest, collected into a packet, and cast off. Mr. Ren- 
nie, the author of a very interesting book on insect arch- 
itecture, describes a process of this kind which he ob- 
served on board of a steam-boat. It was a geometric 
Spider, that is, one that forms its web of regular circular 
lines. The web or net was covered with flakes of soot. 
“Some of the lines,” he says, “she dexterously stripped 
of the flakes of soot adhering to them; but in the greater 
number, finding that she could not get them sufliciently 
clean, she broke them quite off, bundled them up, and 
tossed them over. We counted five of these packets of 
rubbish which she thus threw away, though there must 
have been many more, as it was some time before we 
discovered the manceuvre, the packets being so small as 
not to be readily perceived, except when placed between 
the eye and the light. When she had cleared off all the 
sooted lines, she began to replace them in the usual 
Nway.” 
515. Many observations have been made, and experi- 
ments tried, to determine how Spiders transport them- 
selves from tree to tree, across brooks, or even sometimes 
through the air, without any visible starting-point. The 
subject is not entirely cleared up, but it is well ascer- 
tained that they spin out the thread, letting the wind 
take it, trying it occasionally with the feet to decide 
whether the farther end has attached itself to any object. 
So soon as the Spider finds by pulling on it that it is 
fastened, it runs along upon it, strengthening its cable 
by spinning another as it goes. Spiders have not, as 
some have supposed, the power of projecting their lines 
in opposition to the moving air, but they uniformly put 
their bodies in such position that the line may go with 
the air, that is with the head toward the direction from 
which the breeze comes. They watch the wind as much 
as the sailor does. The little gossamer Spiders let their 
lines, like balloons, carry them off into the air, breaking 
loose from the objects on which they stand when they 
