ON AERONAUTIC SPIDERS. 273 
lines, which were often destroyed for the purpose of 
ascertaining whether they would be replaced by 
others or not, with the same facility, apparently, as 
at the time of their capture. It is particularly de- 
serving of notice that these animals, though unable 
to climb up the smooth perpendicular sides of the 
phials on their first introduction, soon contrived to 
traverse the interior of their prisons in every direc- 
tion. 
In order to illustrate their manner of proceeding 
on this occasion, the case of an individual has been 
selected for description, the same method, with a few 
trivial modifications, being pursued by all. Elevating 
the abdomen, and pressing the spinning-apparatus 
against the side of the phial, this spider emitted from 
its papille a little viscid fluid, which, on exposure to 
the air, hardened into a minute, semitransparent 
speck ; then moving to a short distance, and drawing 
out a line after it, one end of which remained fixed 
to the spot it had just quitted, it connected this fila- 
ment with another part of the phial by applying the 
spinners as before. Several lines being thus pro- 
duced, the spider, speedily raising itself upon them 
above the bottom of the phial, promoted its under- 
taking by repeating the process just described, every 
step so gained enabling it to carry its operations still 
higher. From the cylindrical figure of the phial, it 
follows that all the lines attached to its sides by their- 
extremities, such as were vertical alone excepted, 
a 
