THREADS OF SPIDERS. 
369 
The diversity of opinions that still remains upon these 
points, seems to me to arise partly from some naturalists 
having directed their attention to one species of spider, 
whilst others, in endeavouring to ascertain the same facts, 
may have made observations on a different species ; and 
also from their having drawn their conclusions from facts, 
which, though applicable to the same species, yet do not ap- 
ply to it at every period of its existence ; — one having in- 
vestigated the habits of the spider when young, and another 
at a more advanced season of the year, when the insect is 
fully grown, and when both its habits and capacities are 
considerably changed. 
I have, for example, often observed the garden-spider 
when young, ascend by emitting a long line at a right angle 
to that by which it was suspended from any body : but as 
this spider frequently attains to a great size, it cannot, when 
it becomes heavier, rise by any such means. The larger 
the size of this spider, however, (Aranea horticola), the 
greater is the distance to which it is capable of shooting 
out its thread in a straight line. 
When under the influence of a warmer chmate, this spider 
grows to a much greater size than in Britain. In France 
and Belgium I have often met with them about an inch 
long, and three-fourths of an inch broad across the abdomen. 
In the end of September (1817) I had a very favourable 
opportunity of observing a number of these spiders in the 
Botanical Gardens of Ghent and Brussels. It was just be- 
fore winter operations had commenced ; and in the garden 
at Ghent there were a great many tall plants of the Arbor 
Vitae, Cedar of Lebanon, and Cypress ; and the spaces 
between them were thickly occupied by the webs of very 
large geometric spiders. These spaces were sometimes 
about ten and twelve feet across ; and the circular parts of 
the webs were apparently about a foot and a-half or two 
VOL. VI. A a 
