1 5 o THE WALKS ABROAD OF 



traced its steps, making use of this slender thread as 

 a bridge, and adding a new thread as required. Then 

 when this portion appeared to it to be sufficiently 

 strong, it prepared the other radiating lines in a 

 similar manner, adding finally the concentric threads. 

 There then only remained for construction the hiding- 

 place in which the proprietor of the web lies in 

 ambush to await the course of events. This den, 

 made out of a leaf that the spider is able, by means 

 of its silk, to roll into the form of a cylinder, is 

 arranged in such a manner that the creature in it 

 is made aware of the slightest shock that may be 

 communicated to the web, and also so that it can run 

 out at the first indication and pierce with its veno- 

 mous jaws any unfortunate insect that has allowed 

 itself to be captured. 



The spider's web is not in reality formed by weav- 

 ing : it is simply gummed, and Le*on did not fail to 

 point this out. " The substance of which the silk is 

 formed is," he said, " a sort of viscous gum, secreted 

 by a gland, and issuing by four mammillae, pierced 

 by a multitude of little holes. Each thread, although 

 it appears single to the naked eye, is in fact a bunch 

 of threads soldered or gummed together, and drying 

 on contact with the air, after having been secured 

 to the other threads forming the structure of the 

 web. 



" Each species, moreover, has its own way of work- 



