Page:Popular Science Monthly Volume 1.djvu/522

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506
THE POPULAR SCIENCE MONTHLY.

ural history, which has been published in pamphlet form at Port Louis. Landing at Mahé, he penetrated inland, and found upon the slopes of the hills groves of the jamrosa and the guava-tree.

The jamrosa is the favorite food of the curious leaf-fly (Phiyllium siccifolium).

The peculiar dress of this insect enables it to elude the pursuit of the uninitiated. In form they imitate various leaves, and the resemblance is the more striking from the peculiar veining of their wings. They are sometimes over three inches in length, and their legs have curious leaf-like expansions. They hide on the under surface of leaves, and, when disturbed, double themselves up, so as to closely resemble crumpled leaflets. Probably no more perfect illustration of protective resemblance and mimicry is afforded by the animal kingdom, than by this little insect.

Scorpions abound on the islands, but are less dangerous and dreaded than a large spider of the genus Phyrnus. The female of the species, so plenty on the islands, is one-third larger than the male, being about fourteen lines long.

The many-jointed forelegs are of exceeding tenuity, and measure five inches in length.

These spiders attack by springing on their victim, and their bite causes inflammation, sometimes cramp, vomiting and swelling of the whole body. Ammonia is used by the natives as an antidote for their poison.

A species of mason wasp swarms on the islands, and intrudes everywhere. It builds in houses upon suspended strings, in caves, and in every accessible nook.

It is of a bright-brown color and about one and a quarter inch long. Their cells are about half an inch in length, and built of red mud. Like many species of their class in other parts of the world, they have a curious instinct for preparing food for their young, when in the larva state. After the egg is deposited in the cell, it is carefully filled with small spiders, and closed. The spiders are probably paralyzed by being stung. They continue fresh for several weeks, even retaining their natural colors, and afford the necessary food for the young larva.

The author gives a most interesting account of the wonderful palm-tree, the coco de mer. A century ago it was abundant on these islands, now it has nearly disappeared. For one of the nuts of this tree, it is said that the Emperor Rudolph offered 4,000 florins.

These nuts resemble the cocoa-nut in some respects, but are two-lobed, and four or five times larger.

A fine specimen forwarded by Consul Pike to the Long Island Historical Society of Brooklyn, N. Y., is now in its Museum of Natural History.

The tree grows sometimes a hundred feet high, with a slender stem and a ragged head of green and withered leaves. When the young plant attains the age of 20 or 25 years, and before fructification commences, the leaves have attained their greatest size and luxuriance. The stem then begins to rise.

It is nine months after planting before the germ begins to shoot; then, instead of rising directly, it shoots away like a root 15 or 20 feet, when it rises above the surface. Each leaf requires a year's elaboration in sun and air before the next appears. The early Dutch and Portuguese explorers found the immense nuts of this palm floating in the sea, and supposed it to be an ocean product, hence its name coco de mer.

Elevation of Lagoon Islands in the Pacific.—At a meeting of the Geological Society of London, held May 8th, Mr. D. Forbes is reported to have said that, "when in 1859 he spent some months in the Pacific, he had been requested by Mr. Darwin to examine into the evidence as to the origin of atolls by elevation, and had found that the asserted cases of the existence of masses of coral at a considerable elevation above the sea merely arose from blocks having been transported inland by the natives."

He, however, thought it possible that elevations had taken place in some instances.

The report, which is given in Nature for May 23rd, undoubtedly fails, on account of its brevity, to express clearly the remarks and meaning of that eminent naturalist.

It is, we believe, conceded that the observations of Prof. Dana among the coral-islands of the Pacific are thorough and accurate. On pages 345 and 346 of his re-