Now and then, with its pincers, which appeared through the magnifying-glass to be very large in comparison with the size of the body, it would try to cut the large pincers of the caterpillar. The end of its long legs, as they came round the head and eyes of the caterpillar, seemed to annoy it terribly, to judge by the struggles of the worm. At last the spider succeeded in seizing the base of the right pincer of the caterpillar, and tried to cut it, but in vain. In less than fifteen seconds it returned to the task, and went at the left pincer, but with apparently no better success. Then, after a while, its attacks were directed to a spot between the pincers. He kept at it and kept at it, apparently sucking the blood, till finally, after thirty-seven minutes of deadly conflict, the caterpillar, a mammoth in comparison with the size of the spider, hung dead. Then the spider finished sucking the blood of its victim. While the spider was carrying on this deadly combat, it did not mind me when I touched its web with a little stick: it would just ascend the single thread by which it was suspended, and then, within a few seconds, would return to the fight. After the caterpillar had been killed, when I touched the web it would go up, and remain there for a long time--three or four minutes--before it came down. Finally I took hold of the caterpillar; down came the spider, and with him part of his web. The spider ran along the ground for a few inches, then suddenly rolled itself into a ball and lay apparently dead, the legs being twisted round the body. It appeared to me that the spider thought a wasp was going to attack it, and thus protected itself. After a little while I came to look at the poor dead caterpillar, and saw a few ants hard at work carrying it off somewhere to be devoured. Among the great many species of spiders there are some which are very curious. Among the most remarkable are those which burrow holes in the ground and live in them. These ground-spiders are short, and have powerful fangs and legs. Several species of spiders have short legs, and flat, oval bodies, surrounded by pointed spurs, looking, when taken from their webs, more like bugs than veritable spiders. The cave in which the burrow spiders live is but a few inches long, built in the shape of a tube, from the opening of which they watch for their prey. The interior of the burrow is like felt, and is so arranged that it forms a tunnel that prevents the earth from falling in. Some of the burrow spiders are called trap-door spiders, on account of the curious way in which the entrance of their abode is guarded. A trap-door closes the entrance. This door is made of the same material as the interior of the tube, to which it is attached by a kind of hinge, by which it falls squarely upon it. This trap-door is made to protect the spider from its enemies, among which are wasps and many species of ants. These latter sometimes make short work of a spider.