VALUABLE PRODUCTS FROM MAMMALS 35 



Elephants yield most of the commercial ivory used in the manufac- 

 ture of billiard balls and other articles. A great deal of fossil mam- 

 moth ivory is obtained from the frozen soil of Siberia and some from 

 Alaska and Yukon Territory. Digby 45 says he saw 1000 pairs of 

 mammoth tusks in Siberia in one year. In 1899 ^ was estimated that 

 100,000 elephants, "a procession 180 miles long," were killed annually 

 for their ivory, and Carey says that notwithstanding the efforts to 

 protect them by law they are still being slaughtered, $250,000 worth 

 of tusks being annually smuggled out of British Africa. 46 Walrus ivory 

 is also much used, but those animals, too, have greatly diminished in 

 numbers. Many of the ivory articles sold to tourists in the Northwest 

 are said to have been made of mammoth ivory, but some are walrus 

 ivory. The "whitest and hardest ivory known" is that of hippopota- 

 mus teeth. 47 



5 Digby, The mammoth and mammoth hunting in Northeast Siberia, 1926. 



46 Lucas, Ann. Rept. U. S. Natl. Museum for 1889, p. 611. Carey, Journ. Mam- 

 malogy, vn, 83, 1926. Lang, ibid., rv, 163, 1923. Phillips, ibid., vi, 130-131, 1925. 



47 Jennison, Natural History: animals, p. 308, 1927. 



