1891. ] NEW YORK ACADEMY OF SCIENCES, 73 
ing a series of special papers published 1837-42, were contribu- 
tions of the highest importance, and the first careful, systematic 
work on any special groups of American mammals by an Amer- 
ican writer. 
Incidentally important contributions had been made by nu- 
merous foreign authors, but it would carry us far beyond our 
present scope to consider them in detail. 
Baird began to write on North American mammals as early as 
1852, his work culminating in 1857 in his great work already 
mentioned—a work which gave him pre-eminent standing as.an 
authority, and which still remains the basis from which present 
investigators take their departure. 
Baird’s volume included only the land mammals, exclusive of 
the bats, which, with the seals and Cetacea, were not treated. With 
these several groups omitted, Baird recognized about 220 species 
as entitled to a place in the list of North American mammals, 
nearly twice the number given by Harlan in 1825. Thirty-six 
-othersare mentioned as having been attributed to North America, 
which he was unable to recognize. A few of these are extra- 
limital, but the greater part are either purely nominal, or so 
poorly described as to render their recognition impossible. 
Baird treated the subject exclusively from the systematic side, 
there being nothing in his work relating to the habits of the 
species. Classification, and all questions of synonymy and no- 
menclature, were treated exhaustively; specific and generic char- 
acters were presented in detail and with great discrimination. 
As a technical treatise the work remains a monument to the 
industry and sagacity of its talented author, and, considering its 
extended scope, has not been excelled by any work, in any coun- 
try, on systematic mammalogy. It was illustrated by sixty lith- 
ographic plates and nearly forty woodcuts, relating mainly to 
cranial, dental, and other structural characters. In 1860 the 
text was reissued, with a large number of additional plates, some 
of them new, but mostly from other volumes of the Pacific 
Railroad and Mexican Boundary Survey reports. 
Professor Baird brought to his work not only a mind well 
trained in modern methods of research, but he was favored with 
resources in the way of material far beyond what had fallen to 
the lot of any of his predecessors. 
In March, 1853, Congress appropriated $150,000 for the prose- 
eution of surveys by the War Department of various routes 
across the continent, from the Mississippi River to the Pacific 
coast, for the purpose of determining practicable lines for the 
construction of railroads. Six well-equipped parties were placed 
at once in the field, and six others were soon added, each accom- 
