them. They also build their pendent 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 the wasp on the point of a stick. The wasp seized the caterpillar immediately, and commenced biting it from head to tail, soon reducing the soft body to a mass of pulp.

* "Naturalist on the Amazon," p. 222.

Then rolling up

about one-half of the pulp into a ball, it carried 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 the other half was left. To do this, it hovered in front for a few seconds, then took small circles in front, 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 flew 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 the object and soon got hopelessly lost in the thick foliage. Coming out, 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 search; not so, however, for 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 crowd 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 became almost too dark to distinguish them from my stand. Three species regularly frequented the pool, and three others occasionally visited it. The commonest was the Thalurania venusta (Gould), the male of which is a most beautiful bird,-the front of the head and shoulders glistening purple, the throat brilliant light green, shining in particular lights like polished metal, the breast blue, and the back dark green. It was a beautiful sight to see this bird hovering over the pool, turning from side to side by quick jerks of its tail, now showing its throat a gleaming emerald, now its shoulders a glistening amethyst, then darting beneath the water, and rising instantly, throw off a shower of spray from its quivering wings, and fly up to an overhanging bough and commence to preen its feathers. All hummingbirds bathe on the wing, and generally take three or four dips, hovering, between times, about three inches

above the surface.

Sometimes when the last-mentioned species was suspended over the water, its rapidly vibrating wings showing, like a mere film, a speck shot down the valley, swift as an arrow, as white as a snowflake, and stopping suddenly over the pool, startled the emerald-throat, and frightened it up amongst the overhanging branches. The intruder was the white-cap (Microchera parvirostris, Lawr.), the smallest of thirteen different kinds of humming-birds that I noticed around Santo Domingo; being only a little more than two and a half inches in length, including the bill; but it was very pugnacious, and I have often seen it drive some of the larger birds away from a flowering tree. Its body is purplish-red,

with green reflections, the front of its head flat, and pearly white, and, when flying towards one, its white head is the only part seen. Sometimes the green-throat would hold its ground, and then it was comical to see them hovering over the water, jerking round from side to side, eyeing each other suspiciously, the one wishing to dip, but apparently afraid to do so, for fear the other would take a mean advantage, and do it some mischief whilst under water; though what harm was possible I could not see, as there were no clothes to steal. I have seen human bathers acting just like the birds, though from a different cause, bobbing down towards the water, but afraid to dip their heads, and the idea of comicality arose, as it does in most of the ludicrous actions of animals, from their resemblance to those of mankind. The dispute would generally end by the green-throat giving way, and leaving the pugnacious little white-cap in possession of the pool.

Besides the humming-birds I have mentioned, there were four or five other small ones that we used to call squeakers, as it is their habit for a great part of the day to sit motionless on branches and every now and then to chirp out one or two shrill notes. At first I thought these sounds proceeded from insects, as they resemble those of crickets; but they are not so continuous. After a while I got to know them, and could distinguish the notes of the different species. It was not until then that I found out how full the woods are of humming-birds, for they are most difficult to see when perched amongst the branches, and when flying they frequent the tops of trees in flower, where they are indistinguishable. I have sometimes heard the different chirps of more than