34 ECONOMIC MAMMALOGY 



bat roosts in Texas are reported, on inconclusive evidence, to have 

 yielded sufficient guano to be profitable, but that would not be the 

 case in most localities. Bat guano filled some of the rooms in the great 

 Carlsbad Cavern in New Mexico to a depth of 100 feet, the accumula- 

 tion of many centuries, and it is estimated that 100,000 tons of it, 

 valued at several million dollars, have been removed and marketed. 39 

 Guano obtained from wood-rat nests in the southwestern United States 

 is used by florists. 40 Bones of various land mammals have been ground 

 up for use as fertilizer. It has been estimated that from 1868 to 1880 

 $2,500,000 were paid for bison bones from Kansas, Nebraska and Mis- 

 souri, 41 and an extensive traffic in the bleached bones was carried on 

 from Texas to British America for some years after the bison had 

 practically disappeared from the plains as a living animal. Great piles 

 of bison bones, gathered by Indians and sold to buyers at from $5 to 

 $7 a ton for the manufacture of charcoal, photographed at Saska- 

 toon, Saskatchewan, on August 9, 1890, were estimated to contain the 

 bones of 25,000 individual animals. 42 



Deer antlers are very extensively used in the manufacture of handles 

 for knives and forks, and the waste therefrom is converted into gela- 

 tine or size used in the manufacture of cloth. 43 The American Indians 

 used deer-horn and various bones in making tools for several pur- 

 poses, far back in prehistoric times, as well as during recent years. 

 They have also used porcupine quills and other materials derived from 

 mammals, in the manufacture and ornamentation of clothing, mocca- 

 sins and other articles. Teeth of the wapiti or American elk are much 

 used as the emblem of a great fraternal organization. Many hundreds 

 of these noble animals have been killed solely for their teeth, 44 partly 

 illegally, a practice that has not entirely ceased. The flesh, skins and 

 antlers are left on the ground for fear of detection in attempting to 

 use or remove such bulky things. 



39 Campbell, Bats, mosquitoes and dollars, 1925. Nelson, Bats in relation to the 

 production of guano and the destruction of mosquitoes, U. S. Dept. Agric. Bull. No. 

 1395, 1926- Howard, Mosquitoes and bats, U. S. Public Health Repts., xxxv, 1789- 

 1895, 1920. Bailey, Animal life in Carlsbad Cavern, pp. 2, 5, 108, 113, 1928; Bats of 

 the Carlsbad Cavern, Natl Geog. Mag., XLVIII, 321-330, 1925- 



40 Streator, Commercial fertilizer from wood rat nests, Journ. Mammalogy, xi, 

 318, 1930. 



41 McAllister, California Fish and Game, xiv, 155, 1928, citing Whitney, Remi- 

 niscences of the sportsman, p. 162. 



42 Hewitt, The conservation of the wild life of Canada, Plate x, 1921. 



43 Lantz, U. S. Biol. Surv. Bull. No. 36, 1910. 



44 Graves and Nelson. Our national elk herds, U. S. Dept. Agric. Circular No. 51, 

 1919. Bailey, N. Amer. Fauna, No. 49, p. 33, 1926. 



