500 
part to interruptions by field work and illness, 
and in part to the preparation of matter orig- 
inally intended, and even put in type for the 
present volume, but which it was found would 
too greatly increase its size. This matter, 
embracing the large family of Woodpeckers, 
will appear in Part VI., now in an advanced 
stage of preparation. 
The present volume includes seven families, 
five of which are exclusively American, four 
of them being very numerous in species and 
subspecies. These are the Pteroptochide 
(with only one species in the geographical area 
of the present works), the Formicariide (66 
species and subspecies), the Furnariide (29 
species and subspecies), the Dendrocolaptide 
(41 species and subspecies) and the Trochilide 
(174 species and subspecies). The other two 
families included are the Micropodide (25 
species and subspecies) and the Trogonide 
(23 species and subspecies), the first of wide 
distribution throughout the world, the other 
common to all tropical regions. The same 
careful treatment in respect to technical de- 
tails that has characterized the previous vol- 
umes is still maintained, as are the biblio- 
graphic references, which give at a glance the 
history of the species and higher groups as 
treated by preceding authors. The “keys” 
include many extra-limital genera and species, 
thus greatly widening the scope of the work 
as announced on the title page. There is a 
tendency to recognize as genera many groups 
usually treated as subgenera or altogether 
ignored; they are as a rule natural groups and 
their recognition in nomenclature is consistent 
with the present almost universal tendency to 
differentiate slight geographical forms as 
worthy of recognition as subspecies. 
As heretofore, the work is based upon the 
material of the United States National Mu- 
seum plus that of all the principal collections, 
private as well as public, in this country, the 
specimens examined in preparing the present 
volume numbering 14,358, of which about 
6,000 are in the joint collections of the Na- 
tional Museum and Biological Survey. Of 
the more than 8,000 borrowed specimens, 
nearly all were furnished by three institutions, 
SCIENCE 
[N.S. Vou. XXXV. No. 900 
the Museum of Natural History in New York, 
the Museum of Comparative Zoology at Cam- 
bridge and the Carnegie Museum of Pitts- 
burgh. Through this system of cooperation 
the leading museums are benefited as well as 
the author, since the loaned material is re- 
turned bearing the identifications of the lead- 
ing expert on the subject, and in addition the 
results of the author’s investigations as here 
set forth are more comprehensive and rest on 
a firmer basis than would otherwise be pos- 
sible. With even these resources the author 
has to regret that in several of the families a 
number of genera and very many species were 
not available for examination, so his “ effort 
to bring order out of chaos can be considered 
as only partially successful.” 
While the scope of the work is restricted to 
the technicalities of the subject, references are 
made to nests and eggs “where some par- 
ticular style of nest or coloration of eggs is 
characteristic of a group (family or genus), 
as a sort of accessory or supplemental group 
character.” A paragraph is also given in the 
description of each family to a statement re- 
specting the range in size, character of 
plumage, manner of life and nature of the 
food of the species, as well as their number 
and geographical distribution. Thus under 
the family Trochilide are some items of in- 
formation not generally known even to all 
ornithologists, and much less to the general 
reader. 
“Tnhabitants exclusively of America, the 
Humming Birds constitute not only the most 
charming element in the wonderfully varied 
bird-life of the Western Hemisphere, but, also, 
without doubt, the most remarkable group of 
birds in the entire world. No other group of 
birds is so brilliant in plumage or so different 
from all others in their mode of flight and 
manner of feeding. The general habits of 
Humming Birds are not dissimilar to those of 
birds in general. They are both aerial and 
arboreal, but are unable to progress upon the 
ground or any flat surface by means of their 
legs and feet alone. They perch readily and 
frequently upon trees or bushes, or may even 
cling to rocks or other vertical surfaces; and 
