Page:Supplement to harvesting ants and trap-door spiders (IA supplementtoharv00mogg).pdf/113

 and then, to our great surprise, was suddenly opened again, and the beetle was cast alive and unharmed out of the nest. I immediately secured the insect, which proved to be the common Chrysomela Banksii.

I cannot doubt that this beetle was distasteful in some way to the spider, for it was neither so large nor so powerful as many beetles the remains of which I have found in the spiders' nests, and, besides, it did not escape from the nest, but was distinctly rejected by its captor.

This shows that this spider does not know instinctively what insects to reject and what to take.

This little episode was scarcely ended when I espied a wood-louse (Oniscus) walking down the bank, not far from another of these wafer nests. By a little guidance I managed so to turn its course that this unsuspicious crustacean went straight to the very point I wished, and made as if it would walk over the spider's door; but no sooner was it well within reach than, quick as thought, the spider clutched it and dragged it in. No rejection followed on this capture, and, though I could not actually witness the conclusion of this adventure, I do not doubt that it ended in a tragedy and a supper.

In these two cases, as in all those previously noted, the spiders did not leave the nest nor allow the door to close behind them, but kept it propped up on the abdomen and hindmost pair of legs. In this way the act of seizing their prey, and that of withdrawing into the nest, were almost simultaneous.

In no case did we see any of these spiders out of