128 



HARD WICKE'S SCIENCE- G OS SIP. 



same point (fig. 76, 7). This point of junction is closed 

 by a very wedge-shaped door, the narrowest point of 

 which is at the hinge (fig. jb), which door being 

 fixed at the uppermost point of junction can be used 

 for shutting off the entrance passage or the upper 

 branch (fig. 7a). 



Our next example, N. Manderstjerna , constructs a 

 still more complicated nest (fig. 77, 8). It may be said 

 to consist of two tubes, one of which descends from 

 the door and forms a cavity, the other coming from 

 near the surface of the ground meets this close to its 

 base and then continues for some inches further into 

 the ground (fig. 77). At the point of junction of the 

 two tubes is the inner door, which is very long, and 

 may either divide the two tubes, or cut off the upper 



supposes the next untenanted, and returns by the way 

 it came ; the spider remaining meanwhile comfortably 

 ensconced in the inner part of its dwelling. Next, 

 suppose the inner door to be detected, the spider 

 would hold it to, with all its force and if its 

 strength were then overpowered, pull the door back, 

 and retire within the upper branch. In this case 

 the enemy would either think it had explored the 

 whole tube at last, or another struggle would 

 ensue. 



It must be borne in mind, that the females only 

 inhabit these nests, the males of some of the species 

 being as yet unknown. The young spider after 

 quitting the nest of its mother, and while still quite 

 small, builds an exact copy of hers in miniature. 



Fig. 75- 



Fig. 7 6. 



Fig. 77. 



part of the long tube which forms the branch (fig. 8«). 

 This door is easily mistaken for part of the tube, as 

 it is much grooved on its upper surface (fig. Zb). 

 Strange to say, the bottom part of the external short 

 tube (called the cavity) is often filled up in the 

 nests of old spiders, as if they have no further use 

 for it. 



The only protection the cork spiders have against 

 their enemies, is the manner in which their tight- 

 fitting door is concealed, as well as the firm grip with 

 which they hold it when danger is suspected. But 

 suppose an enemy detects one of the nests last 

 described, and succeeds in entering, the spider rapidly 

 closes the inner door, and the enemy — say a centi- 

 pede—probably walks to the bottom of the cavity, 



I have often cut off the top part of a nest with the 

 door ; and on returning to the same spot after a few 

 days, always found the tube closed by a new door. 



All these spiders are nocturnal in their habits, and 

 search for food at night. As far as yet known, the 

 European ones do not leave their nests, but only 

 snatch in their prey when it comes within reach ; but 

 I have been told by an eminent entomologist, who 

 spent much time in California, that a Californian 

 species (probably C. californica) which builds a cork 

 nest, leaves its nest at night, fixing its door open by 

 spinning a silken thread from it to the bank ; were it 

 not to do so, these doors fit so tightly that it could 

 with difficulty open it on its return. 



