xiit . FORMATION OF PEAT 305 



variety which by some botanists has been considered as 

 specifically distinct. It is remarkable that the same plant 

 should be found on the sterile mountains of central Chile, 

 where a drop of rain does not fall for more than six months, 

 and within the damp forests of these southern islands. 



In the central parts of the Chonos Archipelago (lat. 45°), 

 the forest has very much the same character with that along the 

 whole west coast, for 600 miles southward to Cape Horn. 

 The arborescent grass of Chiloe is not found here ; while the 

 beech of Tierra del Fuego grows to a good size, and forms a 

 considerable proportion of the wood ; not, however, in the same 

 exclusive manner as it does farther southward. Cryptogamic 

 plants here find a most congenial climate. In the Strait of 

 Magellan, as I have before remarked, the country appears too 

 cold and wet to allow of their arriving at perfection ; but in 

 these islands, within the forest, the number of species and great 

 abundance of mosses, lichens, and small ferns, is quite 

 extraordinary.^ In Tierra del Fuego trees grow only on the 

 hill-sides ; every level piece of land being invariably covered 

 by a thick bed of peat ; but in Chiloe flat land supports the 

 most luxuriant forests. Here, within the Chonos Archipelago, 

 the nature of the climate more closely approaches that of 

 Tierra del Fuego than that of northern Chiloe ; for every patch 

 of level ground is covered by two species of plants (Astelia 

 pumila and Donatia magellanica), which by their joint decay 

 compose a thick bed of elastic peat. 



In Tierra del Fuego, above the region of woodland, the 

 former of these eminently sociable plants is the chief agent in 

 the production of peat. Fresh leaves are always succeeding one 

 to the other round the central tap-root ; the lower ones soon 

 decay, and in tracing a root downwards in the peat, the leaves, 

 yet holding their place, can be observed passing through every 

 stage of decomposition, till the whole becomes blended in one 

 confused mass. The Astelia is assisted by a few other plants, 

 — here and there a small creeping Myrtus (M. nummularia) 

 with a woody stem like our cranberry and with a sweet berry 



I By sweeping with my insect-net, I procured from these situations a considerable 

 number of minute insects, of the family of Staphylinidse, and others allied to 

 Pselaphus, and minute Hymenoptera. But the most characteristic family in number, 

 both of individuals and species, throughout the more open parts of Chiloe and Chonos 

 is that of the Tclephorida'. 



X 



