2 EXTINCT AND VANISHING MAMMALS 



been obviated in part by Brouwer's The Organisation of Nature 

 Protection in the Various Countries (1938) - 1 



In the preparation of the accounts of the various mammals 

 treated, the aim has been to assemble and to present in concise form 

 such information as could be obtained on the following points: 



Former range and numbers; 



Present range and numbers (of vanishing species) ; 



Date and rate of disappearance in each country (of species that have 



become extinct, either locally or completely) ; 

 Causes of depletion or extinction, either direct or indirect; 

 Economic uses or importance; 

 Esthetic considerations; 

 The meiBures that have been or might be undertaken for the preservation 



of each vanishing species. 



The primary source of this information has been the published 

 literature. For this purpose, the library of the Academy of Natural 

 Sciences of Philadelphia has been the mainstay. In addition, I have 

 drawn to some extent upon the library resources of the United States 

 National Museum, the Museum of Comparative Zoology, the Ameri- 

 can Museum of Natural History, the Charles Sheldon Collection 

 at Yale University, and the American Philosophical Society. 



An especially valuable source of information has been corres- 

 pondence with zoologists and conservation officials in most of the 

 countries of the Old World. By means of questionnaires, distributed 

 for the most part through the collaboration of the International 

 Office for the Protection of Nature in Brussels, a great mass of 

 fresh and largely unpublished data on the distribution, numbers, 

 economic status, and conservation of mammals has been assembled. 



The unselfish cooperation of these contributors, on a scale per- 

 haps unprecedented in this field, has been an extremely helpful 

 and highly appreciated feature of the investigation. 



Additional material and documents bearing upon the present 

 subject had been accumulating for some years in the office of the 

 American Committee for International Wild Life Protection, and 

 these have been utilized to considerable advantage. 2 



Perhaps few zoologists have had better occasion than myself to 

 become impressed with the inexhaustible nature (and at the same 

 time the inadequacy) of the literature on systematics, distribution, 



1 Special publication of the American Committee for International Wild Life 

 Protection, No. 9. 



2 Dr. Glover M. Allen, in making use of office data of this sort in his com- 

 panion volume on mammals of the Western Hemisphere (1942), seems to have 

 been under the erroneous impression that I was responsible for gathering prac- 

 tically all of them, and consequently he has mentioned my name with the best 

 of intentions but with considerably greater frequency than the facts would 

 warrant. Credit for many of the data is due to sources indicated above. 



