456 7l/r. Blackwall's Observations to ascertain 



next place, carefully ascertained whether their lines had become 

 firmly attached to any object or not, by pulling at them with 

 the first pair of legs ; and if the result was satisfactory, after 

 tightening them sufficiently they made them fast to the twig ; 

 then discharging from their spinners, which they applied to the 

 spot where they stood, a little more of their li([uid gum, and 

 committing themselves to these bridges of their own construct- 

 ing, they passed over them in safety, drawing a second line after 

 them as a security in case the first gave way, and so effected 

 their escape. 



Such was invariably the result when the spiders were placed 

 where the air was liable to be sensibly agitated : I resolved 

 therefore to put a bell-glass over them ; and in this situation 

 they remained seventeen days, evidently imable to produce a 

 single line by which they could quit the branch they occupied 

 without encountering the water at ils base ; though on the re- 

 moval of the glass they regained their liberty with as much 

 celerity as in the instances already recorded. 



This experiment, which from a want of due precaution in its 

 management has misled so many distinguished naturalists, I 

 liave tried with several of the geometric spiders, and always 

 with the same success. Placed under the bell-glass, or in any 

 close vessel, they in vain endeavoured to make their escape 

 from the branch to which they were confined ; but in the dis- 

 turbed air of an inhabited room they readily accomplished their 

 object. 



Instances of long-sustained abstinence from food by insects of 

 the genus Aranea, unaccompanied by any manifest diminution of 

 vital energy, have been given by various observers. In adding 

 another case to the list it is proper to remark, that it must be 

 received solely on my own authority. 



Some of the spiders which produce gossamer were procured 



on 



