said, it will generally touch the disturbing object, however unpromising in appearance, before deciding on its line of action. There is little doubt that many of the numerous hairs and bristles with which its limbs are furnished are distinctly sensory in function.

So much, then, as to the senses of spiders; but what about their “educability”—their power of learning from experience? Here is evidently a wide subject, and a difficult one full of pit-falls for the unwary, but we may nevertheless draw some inferences from the quite elementary experiments on the senses which have been outlined above. A spider drops on account of the sounding of the tuning-fork in its neighbourhood; can it be educated to take no notice of the sound after repeatedly finding that no evil consequences follow? It will perhaps be most instructive to give in a condensed form the results of an actual experiment selected from many performed by two American arachnologists, George and Elizabeth Peckham, whose researches have thrown more light than any others upon the mental equipment of spiders. They had an individual of the small Epeirid species Cyclosa conica under observation for a month, and tested it almost daily with the tuning-fork. At the sound of the fork the spider would drop; when it had recovered itself and returned to the snare the fork would be sounded again, and so on. Now on July 20 the spider fell nine times successively—the last three times only an inch or two—and then took no further notice of the vibrating fork. On subsequent days, until August 5, she fell either five, six or seven times, except on two occasions when a day’s test had been omitted, and then eleven successive falls occurred before the spider ceased to respond. On August 5 she seemed startled at the sound but did not fall, though the fork was sounded nine times. During the remainder of the experiment she generally remained perfectly indifferent to the fork, though on one or two occasions she partially forgot her lesson and dropped a very short distance, immediately recovering herself.

Observe that the basis of educability is memory. For a fortnight, in the case of this particular spider, the lesson learnt on one day seemed to be entirely forgotten the next morning, but thereafter a definite change of habit seemed to result. This does not appear a very great intellectual achievement, but it is by no means despicable, for it must be borne in mind that the habit of dropping when alarmed is almost the only means of defence such a spider possesses, and the instinct which prompts it must be very strongly ingrained. In the words of the experimenters—“Taking this into consideration, it seems remarkable that one of them should so soon have learned the sound of the vibrating fork, and should have modified her action accordingly.”

This single experiment has been here described in some detail largely for the purpose of impressing the reader with the importance of reducing the problem to its simplest terms before any inferences are drawn, and it may well act as a model for any which he may be inclined to undertake on his own account. The more complicated the action, the more likely is the experimenter to read into it motives and mental operations which exist only in his own imagination, and with this warning we must take leave of a subject which might tempt us to encroach too much on an allotted space.

CHAPTER V

TRAP-SNARES AND BALLOONS

There are some interesting variants of the circular snare spun by some exotic Epeirids. One North American species spins it in a horizontal position and then raises the centre, and, by an elaborate system of stay lines from above, converts it into a very accurately shaped dome. A whole group of orb-weavers habitually decorate a sector of the snare with bands of flocculent silk, the object of which for a long time puzzled arachnologists, till it was observed that the spider drew upon this reserve supply of material to wrap up particularly obstreperous insects. It is not unusual for a spider of one of the common species to remove a whole sector of the snare, and by stretching a line from the centre to a place of retreat along the gap thus formed, to provide an unencumbered avenue between its home and its post when on duty. For it must not be forgotten that a spider has to walk warily on its own web, and must avoid, as far as possible, treading on the adhesive lines, or delay and damage to the structure are sure to ensue.

As a rule the circular snares of the different British species are of a very uniform pattern, differing chiefly in the degree of neatness with which they are constructed, and in certain minor details of the “hub,” but we have one spider, Hyptiotes paradoxus—an exceedingly rare species, scarcely ever seen beyond the limits of the New Forest—which makes such a strange snare that it seems a pity to omit all mention of it. It consists of a sector—about one sixth of the full circle—comprising about four radii with cross lines. From the point where the radii meet, a “trap-line” connects the sector to another point of attachment; on, or rather under, this trap-line, the spider takes up its position, hauling it in so as to tighten the web and to leave a slack portion of the line between the points where it holds on by its front and hind legs. When an insect impinges on the web and causes it to tremble, the spider immediately lets go with its fore legs, and the consequent vibration of the web helps to entangle its prey.

The circular snare is the highest form of spinning work attained by spiders, and there is little temptation to expend much time in studying the cruder structures that meet the eye everywhere, but two other types are worth a brief notice. Examine any garden bush—particularly a holly bush, of which the rather rigid leaves provide excellent points of support—and you will find numberless small webs made without any discoverable method, the lines crossing one another at random in all directions. These are the snares of some species of Theridion, and if the webs lack interest the spiders themselves are worth looking at, for they are nearly always quite prettily ornamented.

The other common type of snare is that of Linyphia. It is larger and of more definite design, consisting of a finely-spun hammock stretched horizontally, and surmounted by a labyrinth of irregular lines. Flies entangled in the labyrinth fall upon the hammock in their struggles to escape, and the spider is at hand—always on the under surface of the hammock—to ensure their capture.

Having noted these three common types of snare, let us leave the garden and choose a new field for our observations.

If it is an absolutely calm sunny October morning it will be a suitable occasion for visiting an iron railing, the “knobbier” the better. Early summer will do, but late autumn is generally more fruitful. Almost any railing will serve, but the most satisfactory kind is one with the uprights surmounted by round knobs, and not by spikes. We see at once that the knobs, and the upper rail are glistening with silken lines; many spiders have obviously been at work there. Lines streak the top-rail in all directions, stretch from knob to rail, or from knob to knob if not too distant, while here and there loose ends or streamers flutter gently in the slight currents of air. And closer inspection reveals various small objects moving among this labyrinth of threads. Most of them are spiders, though insects, and particularly weevils, are not wanting. No doubt the weevils know their own