No. 385.) REVIEWS OF RECENT LITERATURE. 67 
not behind the other sections of descriptive zoology; nay, it may 
even be said in truth that it has shown the way to many of them. 
But if the technical part of this science is not behindhand, certainly 
the object itself is not inferior in general philosophic interest to that 
of any other branch of zoology. The study of birds has helped 
throw light on many obscure questions in geology, paleontology, and 
evolution, and the sooner the ornithologist is enabled to settle all the 
little questions of detail, which seem so unimportant to outsiders, 
the sooner will he be able to contribute to the solution of the higher 
problems. The avifauna of this country is probably better known 
than that of any other area of even approximately similar extent, yet 
much is to be done, and in bringing forward its share of the material 
the book under review is valuable to the most advanced student. 
Take the case of Kirtland’s warbler (p. 1070), for instance. The 
history of this bird as there set forth is most suggestive and extraor- 
dinary. The first specimen was taken at sea, off Abaco Island, 
one of the Bahamas, in 1841, and the species has since been dis- 
covered to pass the winters in that archipelago. Ten years later a 
specimen was captured near Cincinnati, Ohio, by Dr. Kirtland, for 
whom Professor Baird named the species. Mr. Butler enumerates 
twenty specimens as having been seen or killed in North America 
since then; all these were observed during the spring or fall migra- 
tions with possibly one exception, and outside of its winter haunts 
this species has not been met with elsewhere. Where does it pass 
the summer; where does it lay its eggs and rear its young? Nobody 
knows, and we have only surmises. If we draw a straight line from 
the northwestern end of the Bahamas to the middle of the state of 
Michigan, we will see that the localities where specimens of this 
curiously rare bird have been found are either situated nearly on 
this line or close to it on both sides, v7z., in South Carolina, Ohio, 
hern Michigan ; while a few others have been taken 
as near Minneapolis, St. Louis, 
all the facts which the ornitholo- 
have been able to bring together 
Indiana, and sout 
at points considerably off the line, 
and Washington, D. C. These are 
gists, in spite of the utmost efforts, 
during a search of nearly fifty years! And what do these facts sug- 
gest? First, let it be stated, that nearly all the facts have been 
brought to light by non-professional observers; next it may be noted 
that as ornithology became more popular, and amateurs more numer- 
ous, the observations also became more frequent; it is also highly 
suggestive that the country between South Carolina and Ohio, through 
which the annual migrations of this bird almost to a certainty take 
