Inception of his Famous Theory. 27

In this island robber the observer must have found a suggestion for his famous theory of the struggle for existence and the survival of the fittest. The author has watched a similar scene in the Gulf of Mexico, where the Grapsus would attack even the birds. Sir W. Symonds states that he has witnessed the same at St. Paul's, the crab dragging young birds away to devour them.

Darwin found little of interest here from a botanical standpoint, not even a single plant or lichen appearing, though several spiders, flies, moths, and beetles made the barren rock their home. If St. Paul's was deficient in vegetation, it abounded in marine forms of interest, the vast area of submerged rock, with its sea-weed masses, affording ample ground for fishes of infinite variety, while sharks were so plentiful that it was a constant struggle between them and the men. The moment an edible fish was hooked a watchful shark rushed at it, carrying it away before it could be taken in, this occurring so frequently that one man was required to fight these pirates of the sea while another hauled in the fish.

These days were marked by indefatigable energy on the part of the young naturalist. When not investigating or peering among the rocks with hammer or collecting-glass in hand, he was at work in his cabin studying the strange animals he had found, and making notes in his log, as to the colour, habits, and the thousand and one points of interest to the lover of science.

From St. Paul's the Beagle bore away for Fernando de Noronha, a desolate ancient volcanic rock upon.

which Darwin landed with great difficulty, owing to the heavy sea, and found to be completely covered with a dense jungle hard to cross or penetrate. It was in this neighbourhood that the young naturalist underwent the experience of crossing the line. Neptune came aboard, as usual, and claimed as a victim every one who had not crossed the equator. Darwin submitted with his accustomed good-humour; was lathered with soft-soap and tar, then shaved with a saw, and finally dumped unceremoniously into a sail full of water, having as a consolation the reflection that he was but one of many predecessors.

On the last day of February the Beagle made Bahia, where Darwin for the first time found himself in a purely Southern country with a wealth of tropical verdure on every hand. The ocean teemed with animal life, new and striking to his eye, while it was but a step into the tropical forest, where vegetation ran wild and flourished with a rank exuberance that he had never dreamed of. In his Journal he penned the following: "Delight itself, however, is a weak term to express the feelings of a naturalist who, for the first time, has wandered by himself in a Brazilian forest. The elegance of the grasses, the novelty of the parasitical plants, the beauty of the flowers, the glossy green of the foliage, but, above all, the general luxuriance of the vegetation, filled me with admiration. A most paradoxical mixture of sound and silence pervades the shady parts of the wood. The noise from the insects is so loud that they may be heard even in a vessel anchored several hundred yards from the shore; yet within the recesses of the