S82 Professor Buckland on the Bones of Mastodon, ^c. from Ava. 



where the left hank of the river presents a diff of several miles in length, 

 generally perpendicular, and not exceeding eighty feet in height. At the 

 bottom of this cliff the strand was dry, and on it were found specimens of 

 petrified wood and bones, that had probably fallen from the cliff in the course 

 of its decay ; but no bone was discovered in the cliff itself by Mr. Crawfurd 

 and Dr. Wallich : nor were they more fortunate in several places v>'here they 

 dug in search of bones in the adjacent district. This district is composed of 

 sand-hills that are very sterile, and is intersected by deep ravines : among the 

 sand are beds of gravel often cemented to a breccia by iron or carbonate of 

 lime; and scattered over its surface at distant and irregular intervals, were found 

 many fragments of bone and mineralized wood, in some instances lying entirely 

 loose upon the sand, in other cases half-buried in it, with their upper portions 

 I)rojecting, naked, and exposed to the air ; they appeared to have been left in 

 this condition, in consequence of the matrix of sand and gravel that once 

 covered them undergoing daily removal by the agency of winds and rains, 

 and they would speedily have fallen to pieces under this exposure to atmo- 

 spheric action, had they not been protected by the mineralization they have 

 undergone. 



On examining many of the ravines that intersect this part of the country, 

 and which were at this time dry, the same silicified wood was found projecting 

 from the sand banks, and ready to drop into the streams ; from the bottom of 

 which the travellers took many fragments, that had so fallen during the gradual 

 wearing of the bank, and lay rolled and exposed to friction by the passing 

 waters. Some of these stems were from fifteen to twenty feet in length and 

 five feet in circumference. These circumstances show that the ordinary effect 

 of existing rains and torrents is only to expose and lay bare these organic 

 remains, and wash them out from the matrix to which some other and more 

 powerful agency must have introduced them. 



Of the total number of bones in this collection, about one-third have suffered 

 from friction; and of the remainder, nearly all appear to have been broken 

 more or less, before they were lodged in the places where Mr. Crawfurd found 

 them irregularly dispersed. Many fragments also of the ivory have been 

 rolled considerably ; but no one specimen of that substance, or indeed of any 

 bone in this collection, has been reduced to the state of a perfect pebble : 

 from this circumstance we may infer, that the waters which produced the 

 rolling they have undergone, were not in violent action during any very pro- 

 tracted period of time. 



Many of the larger bones and some of the small ones have masses of stone 

 adhering to them, which afford specimens of the matrix in which they were 



