TRACHEATES 2 1 7 



When a garden -spider is preparing its web, it first 

 climbs to a high point, gives out two threads from its 

 spinning glands and attaches them. It then lets itself 

 down by the two, either to a branch that lies right 

 below it or in a slightly oblique direction ; it accom- 

 plishes the latter movement by swinging itself about. 

 One of the two threads is again attached and drawn 

 tight ; the other is bitten off, and is carried by the wind 

 until it reaches a branch that lies on a level with the 

 upper point. The spider crawls up it, draws it tight, 

 and attaches it. It then lets itself down and prepares 

 the second vertical thread. It furnishes the horizontal 

 thread either in the way we have described or by 

 making a circuit, passing from one point to the other 

 on the ground, spinning its thread all the time and 

 drawing in the long thread v/ith its fore - legs and 

 fastening it. When it has thus prepared the frame of 

 the net, it runs to the centre of the horizontal thread, 

 and lets itself down vertically to the lower one, and thus 

 forms the diameter-line. Then come the radii from the 

 centre ; these are fastened to all the required points, 

 when the spider has reached them by means of the 

 existing threads. Last of all the concentric lines are 

 made by passing from one radial line to another. The 

 whole web is often made in a single night. 



The work of the house-spider is simpler. It draws 

 threads backwards and forwards across a corner, and 

 lurks in the tube it has spun. Very remarkable, again, 

 is the conduct of the large water-spider. It breathes 

 the air, although it lives in the water, and has in the 

 hairy coat that clothes its abdomen a means of retaining 



