Ch. VIII.

SPIDERS THE PREY OF WASPS.

133

of 1857 in North Wales, where the foxglove was very abundant, and watched the flowers throughout the season, but only once saw a small bee reach the nectary, though many were seen trying in vain to do so.

Great attention has of late years been paid by naturalists to the wonderful contrivances amongst flowers to secure cross fertilisation; but the structure of many cannot, I believe, be understood, unless we take into consideration not only the beautiful adaptations for securing the services of the proper insect or bird, but also the contrivances for preventing insects that would not be useful from obtaining access to the nectar. Thus the immense length of the Angræcum sesquipedale of Madagascar might, perhaps, have been more easily explained by Mr. Wallace, if this important purpose had been taken into account.

The tramway in some parts was on raised ground, in others excavated in the bank side. In the cuttings the nearly perpendicular clay slopes were frequented by many kinds of wasps that excavated round holes of the diameter of their own bodies, and stored them with stingparalysed spiders, grasshoppers, or horse-flies. Amongst these they lay their eggs, and the white grubs that issue therefrom feed on the poor prisoners. I one day saw a small black and yellow banded wasp (Pompilus polistoides) hunting for spiders; it approached a web where a spider was stationed in the centre, made a dart towards it-apparently a feint to frighten the spider clear of its web; at any rate it had that effect, for it fell to the ground, and was immediately seized by the wasp, who stung it, then ran quickly backwards, dragging the spider after it, up a

branch reaching to the ground until it got high enou when it flew heavily off with it. It was so small, the spider so heavy, that it probably could not h raised it from the ground by flight. All over the w there are wasps that store their nests with the bodie spiders for their young to feed on. In Australia, I o witnessed a wasp combating with a large flat spider' is found on the bark of trees. It would fall to ground, and lie on its back, so as to be able to gra with its opponent; but the wasp was always the vict the encounters I saw, although it was not always alle to carry its prey off in peace. One day, sitting on the s banks on the coast of Hobson's Bay, I saw one drag. along a large spider. Three or four inches abov hovered two minute flies, keeping a little behind, advancing with it. The wasp seemed much distur by the presence of the tiny flies, and twice left its p to fly up towards them, but they darted away imm‹ ately. As soon as the wasp returned to the spider, th they were hovering over and following it again. At la unable to drive away its small tormentors, the wa reached its burrow and took down the spider, and t two flies stationed themselves one on each side t entrance, and would, doubtless, when the wasp we away to seek another victim, descend and lay their ow eggs in the nest.

The variety of wasps, as of all other insects, was ver great around Santo Domingo. Many made papery nests. hanging from the undersides of large leaves. Others hung their open cells underneath verandahs and eaves of houses. One large black one was particularly abundan: about houses, and many people got stung by them.

Ch. VIII.]

INSTINCT AT FAULT.

135

They also build their pendant nests in the orange and lime trees, and it is not always safe to gather the fruit. Fortunately they are heavy flyers, and can often be struck down or evaded in their attacks. They do good where there are gardens, as they feed their young on caterpillars, and are continually hunting for them. Another species, banded brown and yellow (Polistes carnifex), has similar habits, but is not so common. Bates, in his account of the habits of the sand-wasps at Santarem, on the Amazon, gives an interesting account of the way in which they took a few turns in the air around the hole they had made in the sand before leaving to seek for flies in the forest, apparently to mark well the position of the burrow, so that on their return they might find it without difficulty. He remarks that this precaution would be said to be instinctive, but that the instinct is no mysterious and unintelligible agent, but a mental process in each individual differing from the same in man only by its unerring certainty.* I had an opportunity of confirming his account of the proceedings of wasps when quitting a locality to which they wished to return, in all but their unerring certainty. I could not help noting how similar they were to the way in which a man would act who wished to return to some spot not easily found out, and with which he was not previously acquainted. A specimen of the Polistes carnifex was hunting about for caterpillars in my garden. I found one about an inch long, and held it out towards it on the point of a stick. It seized it immediately, and commenced biting it from head to tail, soon reducing the soft body to a mass of pulp. It rolled up about one-half of

* "Naturalist on the Amazon,” p. 222.

it into a ball, and prepared to carry it off. Being at the time amidst a thick mass of a fine-leaved climbing plant, it proceeded, before flying away, to take note of the place where it was leaving the other half. To do this, it hovered in front of it for a few seconds, then took small circles in front of it, then larger ones round the whole plant. I thought it had gone, but it returned again, and had another look at the opening in the dense foliage down which the other half of the caterpillar lay. It then few away, but must have left its burden for distribution with its comrades at the nest, for it returned in less than two minutes, and making one circle around the bush, descended to the opening, alighted on a leaf, and ran inside. The green remnant of the caterpillar was lying on another leaf inside, but not connected with the one on which the wasp alighted, so that in running in it missed it, and soon got hopelessly lost in the thick foliage. Coming out again, it took another circle, and pounced down on the same spot again, as soon as it came opposite to it. Three small seed-pods, which here grew close together, formed the marks that I had myself taken to note the place, and these the wasp seemed also to have taken as its guide, for it flew directly down to them, and ran inside; but the small leaf on which the fragment of caterpillar lay, not being directly connected with any on the outside, it again missed it, and again got far away from the object of its search. It then flew out again, and the same process was repeated again and again. Always when in circling round it came in sight of the seed-pods down it pounced, alighted near them, and recommenced its quest on foot. I was surprised at its perseverance, and thought it would have given up the

Ch. VIII.]

HUMMING-BIRDS.

137

search; but not so, it returned at least half-a-dozen times, and seemed to get angry, hurrying about with buzzing wings. At last it stumbled across its prey, seized it eagerly, and as there was nothing more to come back for, flew straight off to its nest, without taking any further note of the locality. Such an action is not the result of blind instinct, but of a thinking mind; and it is wonderful to see an insect so differently constructed using a mental process similar to that of man. It is suggestive of the probability of many of the actions of insects that we ascribe to instinct being the result of the possession of reasoning powers.

Where the tramway terminated at San Benito mine, the valley had greatly contracted in width, and the stream, excepting in time of flood, had dwindled to a little rill. A small rough path, made by the miners to bring in their timber, continued up the brook, crossing and recrossing it. The sides of the valley were very steep, and covered with trees and undergrowth. The foliage arched over the water, forming beautiful little dells, with small, clear pools of water. One of these was a favourite resort of humming-birds, who came there to bathe, for these gem-like birds are very frequent in their ablutions, and I spent many a half-hour in the evenings leaning against a trunk of a tree that had fallen across the stream four or five yards below the pool, and watching them. At all times of the day they occasionally came down, but during the short twilight there was a mass of bathers, and often there were two or three at one time hovering over the pool, which was only three feet across, and dipping into it. Some would delay their evening toilet until the shades of night were thickening, and it