66 PHILOSOPHICAL SOCIETY OF WASHINGTON. 
always indicated. The text comprised not only diagnoses and de- 
scriptions of each species, but extended and elaborate commentary, 
comparisons and criticisms. 
In this learned and sagacious work Professor Baird was aided by 
Cassin and Lawrence, two of the leading ornithologists of America. 
It exerted an influence perhaps stronger and more widely felt than 
any of its predecessors, Audubon and Wilson not excepted, and 
marked an epoch in the history of American ornithology. The 
data original to and embodied in this work have been used again 
and again by subsequent writers with various modifications. Such 
a monument of original research is likely to remain for an indefinite 
period a source of inspiration to other writers, while its authority 
as a work of reference will always endure. 
The publication of this work rendered possible the studies and 
progress of a large number of persons, who without it would hardly 
have been able to enter the domain of scientific ornithology, but 
who, aided by the book as a standard of reference and by the genial 
correspondence and pregnant suggestions of its author, have made 
reputations of more or less distinction for valuable and permanent 
original investigation. The number of those who profited by this 
stimulation has been very large and in this way arose what has 
been called* the Bairdian School of Ornithologists, a school char- 
acterized by exactitude in matters of fact, conciseness in deductive 
statement, and careful analysis of the subject in all its various 
bearings. Its work is marked by a careful separation of the data 
from the conclusions derived from them, so that conclusions or 
arguments can be traced back to their sources and duly weighed, 
while the writings of the older European school afford little basis 
for analysis. In substance, according to Dr. Stejneger, the Euro- 
pean method required an investigator to accept an author’s state- 
ments and conclusions on his personal responsibility alone, while 
the method originated by Baird furnishes him with tangible facts 
from which to make his deductions. 
These distinctive features were still further developed by the 
publication in 1864-66 of the “Review of American Birds,” a 
work of unequalled merit, displaying in their perfection Professor 
Baird’s wonderful powers of analysis and synthesis, so strongly 
combined in his treatment of difficult problems. Although never 
*Stejneger, Proc. U. S. Nat. Mus., VII, 1884, p. 76. 
