216 GOSSAMER 



with their first pair of legs. If the result was satisfactory, 

 after tightening the line sufficiently, they made it fast to 

 the twig ; then discharging from their spinners, which they 

 applied to the spot where they stood, a little more of their 

 liquid gum, and committing themselves to these bridges of 

 their own construction, they passed over in safety, drawing 

 a second line after them as a security in case the first should 

 give way, and so effected their escape. Such being invari- 

 ably the result when spiders were placed where the air was 

 liable to be sensibly agitated, I resolved to put a bell-glass 

 over them, and in this situation they remained seventeen 

 days, evidently unable to produce a single line by which 

 they could quit the branch they occupied, without encounter- 

 ing the water at its base ; though on the removal of the glass 

 they regained their liberty with as much celerity as in the 

 instances already recorded. This experiment, which, from 

 want of due precaution in its management, has misled so 

 many distinguished naturalists, I have tried with several of 

 the geometric spiders, and always with the same success. 

 Placed under the bell-glass, or in any closed vessel, they in 

 vain endeavoured to make their escape ; but in the disturbed 

 air of an inhabited room they readily accomplished their 

 object.' 



The innumerable threads thus emitted by swarms of 

 young spiders readily rise in the air, as Professor Miall 

 has pointed out, in the same way that ' fine dust rises 

 in moving air and fine sediment in moving water.' 1 It 

 is by this means that the dispersal of young spiders 

 is effected, without which the places where they are 

 hatched would become congested and the food supply 

 would soon give out. 



Spiders are hatched from eggs in full possession of 

 their limbs, and, unlike insects, grow in bulk till they 



1 Round the Year, p. 244. 



