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Show 350 CHONOS A UCHIPELAGO. Jan. 1835. cranberry, but with a sweet berry; another (Empetrum rub1' um) like our heath, and a third (Juncus gmndijlorus) a rush; are nearly the only ones that grow on the swampy surface. These plants, though possessing a very close general resemblance to the English kinds, are botanically different. In the more level parts of the country, the surface of the peat is broken up into little pools of water, which stand at different heights, and appear as if artificially excavated. Small streams of water, flowing under ground, complete the disorganization of the vegetable matter, and consolidate the whole. The climate of the southern part of America appears particularly favourable to the production of peat. In the Falkland Islands, almost every kind of plant, even the coarse grass which covers the whole surface of the island, becomes converted into this substance. I was at first at a loss to imagine how so much peat had been formed; but the conversion of the grass at once explains it. I observed that even some bones of cattle, strewed on the surface, were nearly covered up by the decaying matter at the foot of the blades of withered grass. Scarcely any situation checks its growth ; it overhangs the banks of running streams, and encroaches on the piles of loose angular fragments of quartz rock. Some of the beds are of considerable thickness, even as much as twelve feet: the peat in the lower part is earthy, and. completely altered, and when dry, becomes so solid that it ignites with difficulty. No doubt, although every plant lends its aid in the process, yet the Astelia is the most efficient. It is rather a singular circumstance as b~ing so very different from what occurs in Europe, th~ no kmd of moss forms by its decay any portion of the peat in South America. With respect to the northern limit at which the climate allows of that peculiar kind of slow decomposition which is necessary for the production of peat, I believe that in Chiloe (lat. 41° to 42°), although there is much swampy ground, no well-characterized ~ubstance of this nature Jan. 1835. ZOOLOnY, 351 occurs. But in the Chonos Islands, three degrees further southward, we have seen that it is abundant. On the eastern coast in La Plata (lat. 35°), I was told by a Spanish resident (who had visited Ireland), that he had often sought for this substance, but had never been able to find any. He showed me, as the nearest approach to it which he had discovered, a black peaty soil, so penetrated with roots as to allow of an extremely slow and imperfect combustion. The zoology of these broken islets of the Chonos Archipelago, is, as might have been expected, very poor. Of quadrupeds, two aquatic kinds are common. The Myopotamus Coipus (like a beaver, but with a round. tail) is well known from its fine fur, which is an object of trade, throughout the tributaries of La Plata. It here, however, exclusively frequents salt water; which same circumstance has been mentioned, as sometimes occurring with the great rodent, the Capybara. A small sea-otter is very numerous. This animal does not feed exclusively on fish, but, like the seals, draws a large supply from a small red crab, which swims in shoals near the surface of the water. Mr. Bynoe saw one in Tierra del Fuego eating a cuttle-fish ; and at Lowe's Harbour another was killed, in the act of carrying to its hole a large volute; and this was the only specimen of that shell which was procured. At one place I caught in a trap a singular little mouse ; it appeared common on several of the islets, but the Chilotans at Lowe's Harbour said that it was not found in all. What a succession of chances,* or what changes of level, must have been brought into play, thus to spread these small animals throughout this broken archipelago! In all parts of Chiloe and Chonos, two very strange birds occur, which have many points of affinity with the Turco * Many rapacious animals bring their prey alive to feed their young. Are there any instances on record of such a habit among owls or hawks? If so, in the course of centuries, every now and then, one might escape from the young birds. Some such agency is wanted, to account for the distribution of the smaller gnawing animals on islands near to each other. |