256 ABOUT SPIDERS AND THEIR WEBS. 



them. The plate, therefore, forms a door with a silken 

 hinge, and so accurately is it constructed, that when 

 it is closed the upper surface is exactly level with the 

 ground. 



The spider takes care to cover the upper surface 

 with earth exactly resembling the soil in which the 

 burrow is sunk, even imitating the irregularity and 

 roughness with astonishing fidelity, and fixing lichens on 

 it just as the chaffinch does on its nest. So perfectly is 

 this done that to discover a closed trap-door is almost 

 impossible. 



Even when the eye has been directed to the exact 

 spot, it is not easy to find the door. If, however, it 

 be found, and an attempt be made to open it, a toler- 

 ably strong resistance will be experienced. This is 

 caused by the inhabitant, which holds firmly with its 

 forelegs to the door and its hind legs to the lining of its 

 web, and resists as long as it can. 



So firmly does it retain its hold, that when the nest 

 has been pulled out of the soil and torn asunder, the 

 spider has come away with the upper portion, still hold- 

 ing the door against its foe. 



I have already mentioned that the spider always 

 chooses a sloping surface for its burrow. The hinge is 

 invariably placed upon the highest point, so that when 

 the door is opened and the spider issues forth, the door 

 is self-acting and shuts by its own weight. 



In the British Museum there is a remarkable example 

 of a burrow with two trap -doors, one in the usual 



