Now in the whole range of animal instinct there is nothing more remarkable than the manner in which the solitary wasps have learnt to solve this problem. The solution lies in so stinging the victim that it is paralysed but not killed, and though quite unable to move, it neither shrivels nor decays, but remains perfectly sound and edible for two or three weeks. To accomplish this result the wasp acts as though it possessed a knowledge of the minute anatomy of its victim, and knew to a hair’s breadth the position of the principal nerve ganglia which control its actions. Into these it unerringly thrusts its sting. But even accuracy of aim is not everything; there must be the finest discrimination in the severity of the wound. A slight excess, and the animal is killed; too timid a thrust will not destroy movement. When the delicate operation has been successfully performed, the paralysed spider is dragged into the cell, placed on its back, and an egg carefully deposited at the base of its abdomen, after which the cell is sealed up. Some wasps, instead of providing a single large spider, store their cells with a number of smaller victims, all rendered limp and motionless. In attacking a spider the first action of one of these wasps is to remove it from its natural environment. A garden-spider in its web, or a burrowing spider in its tunnel are more or less formidable, but if the one can be thrown down, or the other dragged forth into the open, they are well-nigh defenceless. Therefore in attacking an Epeirid the wasp first darts at it, seizes a leg, and attempts to jerk it out of the web. If unsuccessful, the spider will now be on its guard, and the wasp leaves it and tries the same manœuvre on another individual. Taken by surprise, it is instantly thrown to the ground, and can then offer no effectual resistance. Even the large “bird-eaters” fall victims to these terrible foes. CHAPTER XV SOME CONCLUDING REFLEXIONS In the foregoing pages we have been able to deal with very few out of the vast number of known spiders; yet the examples we have chosen for study are fairly typical of some of the more important groups, and calculated to give a tolerably just idea of the general economy of the tribe. In any case even such a fragmentary study as the present gives us food for thought. There is a question which the writer has so often been asked that he is inclined to deal with it in anticipation, though perhaps he is wronging his readers in supposing that they desire to propound any such conundrum. This question is: What is the _use_ of spiders?