Narrative of the surveying voyages of his majesty's ships Adventure and Beagle (vol.3)

Jan. 1835. zoology. 351 occurs. But in the Chonos Islands, three degrees further southward, we have seen that it is abundant. On the east- ern coast in La Plata (lat. 35°), I was told by a Spanish resi- dent (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 dis- covered, 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 Archi- pelago, is, as might have been expected, very poor. Of quadrupeds, two aquatic kinds are common. The Myopo- tamus Coipus (hke a beaver, but with a round tail) is well known from its fine fur, which is an object of trade, through- out the tributaries of La Plata. It here, however, exclu- sively 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 jDlay, thus to spread these small animals throughout this broken archi- pelago ! 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 tiieir 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.