100 TRAP-DOOR SPIDERS. 



pendage at its lower end, the whole being made of 

 earth enclosed in a case of silk.* When the lower 

 door is drawn back so as to close and conceal the en- 

 trance to the branch, it lies in the same plane, and 

 closely corresponds in curvature with the lining of 

 the main tube and almost appears to form part of it 

 (fig. A, Plate X. p. 100, and fig. B 1, Plate XI. p. 105). 



When digging out these nests, after carefully re- 

 moving the upper portion, I have frequently seen the 

 lower door move adross and block up the main tube 

 in a mysterious manner, it being in reality pushed by 

 the spider from below, and she may sometimes be cap- 

 tured at her post with her back set against the door. 

 More frequently, when the spider finds that resistance 

 is hopeless and sees the earth crumbling in, she drops 

 to the bottom of her nest and lies there helpless, with 

 her legs folded against her body like an embryonic 

 creature ; some, however, more savage than their 

 neighbours, fly out and strike at the intruder with 

 their fangs. 



What then, it may be asked, is the use of the 

 branch ? I do not think that we can draw any safe 



* Since writing the above I have learned, thanks to a better method which 

 I have recently adopted for preserving the nests for examination, that some- 

 times the lower door, instead of being free within the tube and only attached 

 to the lining by the hinge, is surrounded on either side bj' a delicate silk 

 web, which extends from either edge of its lower surface to the silk walls of 

 the tube below and forms a sort of double gusset. This admits of the 

 movement of the lower door in the way described above, but perhaps serves, 

 together with the solid appendage at the extremity of the free end of the door 

 (that away from the hinge), to prevent the door from being driven too far in 

 an upward direction and thus becoming so tightly jammed as to make the 

 spider a prisoner in her own nest. I think it possible that the lower door 

 is always attached to the tube in this way, but, as it parts readily from the 

 silk on either side when the earth which supports the tulie is removed, it 

 very frecpiently appears to be free, as I have represented it in Plates IX. , 

 X., and XI. 



