400 IVORY AND THE ELEPHANT 



mammoth and mastodon ivory we have described was 

 accumulated by a special collector, who obtained the mate- 

 rial from various sources. 



It is the even, constant temperature due to being buried 

 in ice or frozen ground that has aided to preserve mammoth 

 ivory. A temperature with but slight variations tends to 

 preserve ivory; it is variation from extreme cold to extreme 

 heat that injures all varieties of this material, and not the 

 action of a constant temperature, either hot or cold. The 

 tusk, lower jaws, vertebral bones, and the shafts of the limb 

 bones of the mammoth and mastodon are generally pre- 

 served in remarkable perfection, but the skulls are usually 

 decayed, being made up of diploic or cancellous bone tissue. 

 As this tissue is filled with air spaces, the skulls often break 

 soon after discovery, although found in perfect condition. 



Fragments of fossil ivory thoroughly silicified and im- 

 pregnated with manganese, so as to have acquired a "moss 

 agate" eiffect, have been found in western Kansas, in the 

 divide between the Smoky Hill River and the Republican 

 River, north of Trego and Buffalo Park. The character- 

 istic ivory structure was clearly apparent in these fossil 

 pieces.* 



Although it is doubtful that any records exist of the length 

 of the elephant tusks secured by the hunters of Egyptian 

 or Assyrian times, two tusks, the longer measuring about 

 2 ft. 5 in. in length, were found by Layard in the North 

 West Palace at Nimroud. Only parts of these tusks have 

 been preserved.! 



At an early period the conquering Romans gained access 

 to some of the accumulated ivory treasures of the East. 

 The historian Livy relates that at the triumph celebrated 



^Communicated by Prof. S. W. Willistoa, Dept. of Paleontologj-, University of Chicago. 



fLayard, "Discoveries in the Ruins of Nineveh and Babylon," London, 1853, Pt. I, 

 p. 195. 



