120 TRAP-DOOB SPIDERS. 



take such materials as come to hand, as these will 

 ordinarily serve for the concealment of their door. 



However, these trap-door spiders do seem to exercise 

 some discrimination in the choice of materials ; for I 

 have observed several instances in which, when the 

 door of a cork nest has been removed, if the door was 

 originally covered with moss, moss will again be used 

 in its reconstruction, even though the mouth of the 

 tube be then surrounded by bare earth. 



Thus, for example, in one case where I had cut out 

 a little clod of mossy earth, about two inches thick 

 and three square on the surface, containing the top of 

 the tube and the moss-covered cork door of N. ccEmen- 

 taria, I found, on revisiting the place six days later, 

 that a new door had been made, and that the spider 

 had mounted up to fetch moss from the undisturbed 

 bank above, planting it in the earth which formed 

 the crown of the door.* Here the moss actually called 

 the eye to the trap, which lay in the little plain of 

 brown earth made by my digging. 



I have seen the same thing happen when the door 

 of N. Eleanor a has been removed and replaced, moss 

 being again used in the work of reconstruction. Trap- 

 door spiders in warm weather very quickly replace 

 their trap-doors ; and if you pass by a wall where 

 several nests have been robbed of their doors only 

 a week before, they will usually be found quite perfect 

 again. 



It has been statedf that, if the door of a cork nest 



* Mrs. Boyle first called my attention to tins curious fact, of which I 

 have since seen many examples. I have purposely removed several cork 

 dcors from mossy banks in order to observe this point. 



+ M. Dorthes on the Structure and CEconomy of some Curious Species of 

 Arauea, in Trans. Linn. Soc. (London), II. 88 — 90. 



