845 THE AMERICAN NATURALIST. | [Vor. XXXIX. 
Chapter XI. on Nest-Building is entirely new, as are also in large 
measure those which follow on The Development and Care of the 
Young and on Life and Instinct." The size of the volume has been 
reduced so as to make it serviceable for field use. 
For the serious and minute study of the life of birds at their nests, 
the author's * method" has its great advantages as well as its limita- 
tions. A small tent, described fully in Chapter III, * Tent and Cam- 
era," is erected within arm's length of the nest to be studied and the 
observer is enabled to watch the activities of the birds through a 
small window cut at the proper height in the tent-wall. The camera 
is also used from the shelter of the tent. In cases where the nest 
cannot be conveniently reached from the ground it is removed 
together with the nesting-limb and set up in a favorable spot, where 
it may be readily observed from the tent. The instinct of the parent 
birds to care for their young is so strong that they soon return to 
their charges and, finding that no harm comes from the tent, they 
quickly learn to disregard it entirely. It is important to note, how- 
ever, that such liberties may not be taken with a nest until the young 
are hatched and are a few days old, for if disturbed earlier than this 
the old birds will desert. For this reason the very early life of the 
nestling cannot be so well studied by this method. Professor Herrick 
has used his “method,” with good judgment and in but “four or 
five cases when the nest with its supports has been displaced . . . . have 
the young come to grief, in the course of five vears’ work.” 
The first three chapters of the volume are given to an exposition 
of the “method,” then follow chapters on the nesting habits of the 
robin, the cedar-bird, the red-eyed vireo, the bluebird, the catbird, 
the nighthawk, and the belted kingfisher, with photographic repro- 
ductions of the various activities that take place at the nest. The 
remaining chapters are of a more general nature and treat briefly of 
nest-building, the development and care of the young, life and instinct, 
and the instinct of fear in young birds. From his studies of a num- 
ber of species, the author has come to regard a large part of the activ- 
ities of nesting as instinctive. “Birds seem to follow one line of 
conduct, whether it be building nests, sitting over eggs, or brooding 
and tending the young. until their instinct in any given direction has 
been satisfied, thus normally completing one term of the series before 
passing to the next in sequence .... Each term of the cycle is cap- 
able of analysis into many minor components, differing not only in 
the sexes, but in different species, and subject to change in different 
individuals . ... One instinct may be overdone, as when a bird like 
