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separated to avoid improper crossing and inbreeding and 
in space, that the best conditions may be afforded for 
favorable development of the young, which are attainable 
under the limitations of a zoological garden. 
With the best efforts of our own and similar institutions 
existing in this country and the facilities for exchange of 
specimens, which is growing with the establishment of new 
ones, as well as the private preserves of a few individuals 
who are devoting both time and money to the same pur- 
pose, it cannot be doubted that valuable services may 
be rendered to a cause whose importance is denied by few. 
Perhaps the most practical demonstration of these possi- 
bilities may be found in the statement that in the case of 
the bison alone, probably nine-tenths of all now surviving 
outside of the National Park, are comprised in a few herds 
owned by private individuals and zoological gardens. 
Respectfully, 
ARTHUR ERWIN BROWN, 
Superintendmt. 
Zoological Garden, March 1st, 1891. 
