io8 
Recent Literature. 
[April 
“The facts recorded in this report were obtained from an examination 
of the contents of the stomachs of over 1800 birds, 1608 of which contrib- 
uted results which have been incorporated in the report.” The contents 
of one-half these stomachs were examined fresh, with the hand-lens, the 
rest more leisurely and in greater detail after transferance to alcohol. 
“But had it been possible,” says the author very truly, “to identify specifi- 
cally the 7663 insects, etc., taken from the stomachs of these 1608 birds, this 
would have been by far the smallest part of the task set, for then it would 
be required to command a full and broad knowledge of the economic rela- 
tions of the insects eaten. But with the difficulty solved, we must recognize 
still another, of greater magnitude and higher degree. Because of these 
great difficulties inherent in the task itself, and the ample grounds they 
present for difference of opinion in regard to final conclusions, it has 
seemed very desirable that there should be presented some of those general 
considerations which have served as guides to the classification adopted.” 
These considerations are therefore presented, and very elaborately, in 
the Introduction, which occupies some 30 pages. Bird-food, considered 
in its two broad categories of vegetal and animal, is farther ranged under 
the two leading classes of that, the consumption of which is on the whole 
(1) a service, or (2) an injury, to man. Beneficial services of birds are 
stated and discussed under the following propositions : A bird is beneficial 
when it feeds upon injurious (1) plants, (2) mammals, (3) birds, (4) rep- 
tiles, (5) insects [the real crux of the problem], (6) mollusks, (7) crus- 
taceans and worms, (8) carrion. (We state it very broadly and tersely — 
the author’s own propositions are elaborated and qualified in various 
ways.) On the other hand, a bird is injurious under nearly the same 
number of contrary conditions: as when (1) it destroys or injures useful 
plants; (2) preys on shrews, moles, and bats: (3) upon beneficial birds; 
(4) upon lizards and small snakes ; (5) upon frogs, toads, and salamanders ; 
(6) upon the parasites of noxious animals, especially noxious insects ; ^7) • j 
upon beneficial predaceous insects, spiders, and myriapods; (8) upon car- 
rion insects ; (9) upon beneficial worms. These numerous points receive 
due attention. 
“When it is proposed to utilize birds as insect destroyers, to increase 
the abundance of certain species and to exterminate or hold in check 
others, to encourage the breeding of certain birds in given places and to pre- 
vent others from doing so ; or, when it is proposed to introduce into a 
country a foreign species, other questions than those of food simply must 
be considered.” Some of the more important of these are given by the ! 
author as : (1) The relations held*by the bird to different industries ; (2) 
its food and habits in different localities ; (3) during different seasons ; 
(4) when young and mature ; (5) when and how long the bird is in a given 
locality ; (6) its nesting place ; (7) its other haunts ; (8) its hours of feed- 
ing; (9) methods of obtaining food; (10) situations in which its food is 
obtained; (n) whether or not the bird does an important work which 
other birds are not fitted to do; (12) size and activ&y of the bird; (13) its 
gregariousness or the reverse; (14) its dexterity upon the wing; (15) its 
