Ch. VII.] THE HELICONIDE. 109 their instinct taught them to avoid it, for, although startled, they threaded their way through open spaces and between the webs with the greatest ease. It was one instance of many I have noticed of the strong instinct implanted in insects to avoid their natural enemies. I shall mention two others. The Heliconidæ, a tribe of butterflies peculiar to tropical America, with long, narrow, weak wings, are distasteful to most animals: I have seen even spiders drop them out of their webs again; and small monkeys, which are extremely fond of insects, will not eat them, as I have proved over and over again. Probably, in consequence of this special protection, they have not needed stronger wings, and hence their weak flight. They are also very bold, allowing one to walk close up to flowers on which they alight. There is one genus with transparent wings that frequents the white-flowered shrubs in the clearing, and I have sometimes advanced my hand within six inches of them without frightening them. There is, however, a yellow and black banded wasp that catches them to store his nest with; and whenever one of these came about, they would rise fluttering in the air, where they were safe, as I never saw the wasp attack them on the wing. It would hawk round the groups of shrubs, trying to pounce on one unawares; but their natural dread of this foe made it rather difficult to do so. When it did catch one, it would quietly bite off its wings, roll it up into a ball, and fly off with it. Again, the cockroaches that infest the houses of the tropics are very wary, as they have numerous enemies birds, rats, scorpions, and spiders: their long, trembling antennæ are ever stretched out, vibrating as if feeling the very texture of the air around them; and their long legs quickly take them out of danger. Sometimes I tried to chase one of them up to a corner where on the wall a large cockroacheating spider stood motionless, looking out for his prey ; the cockroach would rush away from me in the greatest fear; but as soon as it came within a foot of its mortal foe nothing would force it onwards, but back it would double, facing all the danger from me rather than advance nearer to its natural enemy. I To return to the spiders: besides the large owner and manufacturer of each web who was stationed near its centre, there were on the outskirts several very small ones, belonging, I think, to two different species, one of which was probably the male of a Thomisus, the males in this genus being much smaller than the females. sometimes threw a fly into one of the webs: the large spider would seize it and commence sucking its blood. The small ones, attracted by the sight of the prey, would advance cautiously from the circumference, but generally stop short about half-way up the web, evidently afraid to come within reach of the owner; thus having to content themselves with looking at the provisions, like hungry urchins nosing the windows of an eating-house. Sometimes one would advance closer, but the owner would, when it came within reach, quickly lift up one of its feet and strike at it, like a feeding horse kicking at another that came near its provender, and the little intruder would have to retire discomfited. These little spiders probably feed on minute insects entangled in the web, too small for the consideration of the huge owner, to whom they may be of assistance in clearing the web. Soon after crossing the muddy Artigua below Pavon, half circle, and each feather widening towards the end makes the semicircle complete around the edge. When catching the ephemerida that play above the water, the tail is not expanded: it is reserved for times of courtship. I have seen the female sitting quietly on a branch, and two males displaying their charms in front of her. One would shoot up like a rocket, then suddenly expanding the snow-white tail like an inverted parachute, slowly descend in front of her, turning round gradually to show off both back and front. The effect was heightened by the wings being invisible from a distance of a few yards, both from their great velocity of movement and from not having the metallic lustre of the rest of the body. The expanded white tail covered more space than all the rest of the bird, and was evidently the grand feature in the performance. Whilst one was descending, the other would shoot up and come slowly down expanded. The entertainment would end in a fight between the two performers; but whether the most beautiful or the most pugnacious was the accepted suitor, I know not. Another fine humming-bird seen about this brook was the long-billed, fire-throated Heliomaster pallidiceps, Gould, generally seen probing long narrow-throated red flowers, forming, with their attractive nectar, complete traps for the small insects on which the humming-birds feed, the bird returning the favour by carrying the pollen of one flower to another. A third species, also seen at this brook, Petasophora delphina, Less., is of a dull brown colour, with brilliant purple ear-feathers and metallic-green throat. Both it and Florisuga mellivora are short billed, generally catching flying insects, and do not frequent flowers so much as other humming-birds. I Ch. VII.] TONGUE OF HUMMING-BIRDS. 113 have seen the Petasophora fly into the centre of a dancing column of midges and rapidly darting first at one and then at another secure half a dozen of the tiny flies before the column was broken up; then retire to a branch and wait until it was re-formed, when it made another sudden descent on them. A fourth species (Heliothrix barroti, Bourc.), brilliant green above, white below, with a shining purple crest, has also a short bill, and I never saw it about flowers, but always hovering underneath leaves and searching for the small soft-bodied spiders that are found there. Two of them that I examined, both had these spiders in their crops. I have no doubt many humming-birds suck the honey from flowers, as I have seen it exude from their bills when shot; but others do not frequent them; and the principal food of all is small insects. I have examined scores of them, and never without finding insects in their crops. Their generally long bills have been spoken of by some naturalists as tubes into which they suck the honey by a piston-like movement of the tongue; but suction in the usual way would be just as effective; and I am satisfied that this is not the primary use of the tongue, nor of the mechanism which enables it to be exserted to a great length beyond the end of the bill. The tongue, for one-half of its length, is semi-horny and cleft in two, Tongue of Humming-bird, with the blades a little opened. the two halves are laid flat against each other when at rest, but can be separated at the will of the bird and form a delicate pliable pair of forceps, most admirably |