4.6 The Structure and Habits of Spiders. 



Two or three inches down the tube is another 

 door, Fig. 22, E, hanging to one side of the 

 tube when not in use ; but, when one tries to 

 dig the spider out from above, she pushes up 

 the lower door, so that it looks as if it were 

 the bottom of an empty tube. 



Another species digs a branch obliquely 

 upward from the middle of the tube, closed 

 at the junction by a hanging-door, which, when 

 pushed upward, can also be used to close the 

 main tube, Fig. 22, F. What use the spider 

 makes of such a complicated nest, nobody 

 knows from observation ; but Mr. Moggridge 

 supposes that when an enemy, a parasitic fly, 

 for instance, comes into the mouth of the 

 tube, the spider stops up the passage by press- 

 ing up against the lower door ; but, if this is 

 not enough, it dodges into the branch, draws 

 the door to behind it, and leaves the intruder 

 to amuse himself in the empty tube. The 

 branch is sometimes carried up to the surface, 

 where it is closed only by a few threads ; so 

 that, in case of siege, the spider could escape, 

 and leave the whole nest to the enemy. 



In these nests the spiders live most of the 



