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. cæmentaria, 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.[1] 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. Eleanora 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 stated[2] that, if the door of a cork nest
- ↑ Mrs. Boyle first called my attention to this curious fact, of which I have since seen many examples. I have purposely removed several cork doors from mossy banks in order to observe this point.
- ↑ M. Dorthès on the Structure and Œconomy of some Curious Species of Aranea, in Trans. Linn. Soc. (London), II. 88-90.
