How Animals Work. 



the neck of a bottle. This type is called the " single- 

 door" cork nest. In forming the wafer type of door 

 the spider covers the entrance to the nest with a closely 

 woven sheet of silk, which she afterwards bites away 

 round the edge, except at the point where the hinge 

 is to be. The cork type of door is much more com- 

 plex. First the spider weaves a covering of silk, as in 

 the construction of the wafer door; then she brings 

 earth in her jaws and lays it on top, binding it down 

 with a second layer of silk, and this process she repeats 

 until the requisite thickness is obtained. The third 

 type of nest, again, is a single descending silk-lined 

 shaft ; but it has two doors, one of the wafer type at the 

 top, level with the surface of the ground, the second 

 door being at a little distance down the tube. The 

 fourth type of nest is the most complex of all, for the 

 spider constructs in this instance a Y-shaped burrow, 

 one arm of which, however, does not always reach to 

 the surface ; and the second door of this nest, instead of 

 being across the descending shaft at a little distance 

 from the surface, hangs at the fork of the Y in such a 

 manner as to connect the bottom chamber either with 

 the entrance or the blind-ended branch. To the outer 

 surface of the door covering the top of the nest the 

 spiders attach leaves, moss, or small twigs, which most 

 effectually hide the entrance. The Trap-door Spiders 

 appear to be greatly attached to their nests, which they 

 enlarge and repair when needful ; and they begin bur- 

 rowing very early in life, building miniature tubes, 

 which in all respects exactly resemble those of their 

 parents. 



The cork-door nest is the simplest form, and its 



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