996 
same series we have also “ Minnesota Mush- 
rooms,” by Professor Clements. 
A year ago A. O. Garrett, of the Salt Lake 
City High School, published a little book of 106 
pages, entitled “Spring Flora of the Wasatch 
Region,” and including “the eastern edge of 
the Great Basin as far south as Manti” (cen- 
tral Utah). This is now followed with a sec- 
ond, considerably enlarged edition of 139 
pages. It must be very useful to pupils in the 
schools of the region covered. It would be 
still more helpful if not confined to “spring 
plants” alone (“before June 15”). 
Much like the last is the “Spring Flora of 
the Intermountain States,” by Professor Dr. 
Aven Nelson, of the University of Wyoming 
(Ginn), which in 202 pages covers Colorado, 
Wyoming, Montana, Idaho (excepting the 
northern part), a portion of eastern Oregon 
and the northern half of Utah. The treat- 
ment is much like that in the Wasatch Flora, 
and must be equally useful in the much larger 
region included. Here again one wishes that 
the “spring ” limit could be removed. 
Hall’s “ Yosemite Flora” (Elder, San Fran- 
cisco) is a book designed to appeal in paper, 
pictures and binding more to the tourist than 
to the pupils in schools, and yet it must prove 
a most inspiring field manual for pupils for- 
tunate enough to have access to its keys and 
descriptions. While called a Yosemite Flora, 
we are told that it is also “designed to be 
useful throughout the Sierra Nevada Moun- 
tains.” Eleven most artistic plates and 170 
text figures add much to the usefulness of the 
book for the beginner. 
The “ Flora of Nebraska,” published by N. 
F. Petersen, instructor in botany in the 
Louisiana State University, is an attempt to 
name every plant (conifers and flowering 
plants) growing without cultivation in the 
state. It is modeled after Rydberg’s well- 
known “Flora of Colorado,” and like it the 
treatment is by the copious use of keys, by 
means of which the phyla, classes, orders, fam- 
ilies, genera and finally the species are suc- 
cessively found. And after the species is 
determined by this method one finds a little 
paragraph assigned to it containing habitat, 
SCIENCE 
[N.S. Vou. XXXV. No. 913 
distribution and locality data. It will be use- 
ful to high-school pupils, in spite of the rather 
numerous typographical errors, due to the em- 
ployment of a printer unaccustomed to scien- 
tifie printing. 
Here may be mentioned Professor Schaff- 
ner’s “ Key to the Families of Seed Plants ” 
designed to aid his students (Ohio State Uni- 
versity) to distinguish the natural plant fam- 
ilies by carefully devised keys. 
BOTANY IN THE MOUNTAINS 
The University of Colorado Mountain Labo- 
ratory at Tolland, Colo., will hold its session 
this year, beginning June 24 and ending Au- 
gust 2, 1912. There will be a general course 
in field biology, in which both animals and 
plants are considered in relation to their en- 
vironment, and also courses in systematic bot- 
any, ecology and biology of ponds and streams. 
Special attention will be given to research 
work. 
The laboratory is situated in an interesting 
region at an altitude of nearly 9,000 feet. 
Tolland is the station for Boulder Park, a 
mountain valley surrounded by timber-clad 
hills. Within easy reach of the laboratory are 
typical pine and spruce forests, mountain 
meadows, narrow canyons, glacial lakes and 
alpine tundra. In addition to regular daily 
field trips which take the student to these vari- 
ous habitats of animals and plants there will 
be all day excursions by rail to the foothills 
and even to the plains for the purpose of 
making comparative studies of the flora and 
fauna of these localities. Professor Francis 
Ramaley, of the University of Colorado 
(Boulder), is the director of the laboratory. 
Cuarues E. Bessey 
THE UNIVERSITY OF NEBRASKA 
SPECIAL ARTICLES 
NITRATES IN SOILS* 
Tue fertilizing value of materials that we 
now know to contain nitrogen was of course 
1 Paper read by invitation before the Society of 
American Bacteriologists at Washington, Decem- 
ber, 1911. 
