MEGATHERIUM BOULDER FORMATION. 03 



Grreek, megas, great, and therion, beast), which was not less than 

 jighteen feet long and nine feet high. The skeleton is analogous 

 tolhat of animals of the order edentata. The thigh-bone in the 

 megathe'rium is nearly three times as great as the largest known 

 elephant ; the bones of the instep and those of the foot are of cor- 

 responding size, the heel-bone projects back nearly eighteen inches, 

 and the small bones of the foot advanced as much forwards. The 

 third toe is provided with a socket to receive a cla\v, the sheath of 

 which measures thirteen inches in circumference, and the core on 

 which the nail was attached is ten inches in length. The fore 

 limbs were well adapted for grasping the trunk or larger branches 

 of a tree. This animal was slow in its movements, and probably 

 fed on roots, which its teeth were admirably adapted for grinding. 



35. To the diluvial drift are also referred the great collectiens 

 of bones of the Icy ocean, on the coasts of Siberia and on the 

 neighbouring islands : there a number of enormous animals, their 

 flesh preserved through thousands of years, lie buried in sands 

 consolidated by perpetual ice ; in the same situations have been 

 found stags and horses, the elephant and rhinoceros, covered with 

 hair, seemingly indicating that the species which then lived in 

 northern climates were enabled to bear, from being clothed in fur, 

 lower temperatures than those with naked skins which now inhabit 

 southern Asia and Africa. The tusks of these elephants of the 

 ancient world are sought for the ivory they afford, and compete, in 

 commerce, with those of modern elephants. 



It is perhaps to the clilu'vium we must refer those immense masses of 

 rolled debris which contain gold, platina, and the diamond, in Brazil, in 

 Africa, in India, and in the Oural mountains, as well as the arena'ceouw 

 veins of tin in Cornwall and Mexico. 



36. The BOULDER FORMATION, or ERRATIC BLOCK FORMATION 

 also, is regarded as a part of the diluvial drift. A great part of 

 the plain of Switzerland is covered at intervals by fragments of 

 rock, measuring about a cubic yard, which strew the plain, and 

 dot the sides of the Alpine ravines, and rise on the opposite side 

 of the Jura range, even to an elevation of several thousand feet 

 above the sea. The most concentrated distribution of these blocks 

 seems to be near the town of NeuchateL but similar masses are 

 also found on the summit of the Mont Saieve, behind Geneva. 

 It is very remarkable that a belt of fragmentary masses (not few 

 or small, but countless and gigantic), differing entirely in character 

 from the formation on which they rest, should be found lying on a 

 steep, almost precipitous slope of nearly bare or thinly-covered 

 rock. One of the blocks behind Neuchatel, eight hundred and 

 fifty feet above the lake, is of granite, and measures between fifty 



34. What is the position of diluvial drift ? What is the megathe'rium ? 

 ^r>. What other fossils are referred to the diluvial drift ? 

 36. What is the nature of the Boulder formation? 



