62 BOTANICAL GAZETTE [JULY 
North American trees 
Three years ago this journals noticed the appearance of SARGENT’s excellent 
Manual of the trees of North America, which brings into a convenient volume the 
information that is much more elaborated in his great Silva. Now another manual 
of the trees has appeared, bearing the title North American trees, and written by 
Britton and SHAFER.® The very handsome volume is made bulky by the heavy 
paper, so that it will have to be used more as a standard dictionary than as a 
handy manual. 
The distinct mission of the volume, however, is to present the trees in language 
so free from technical terminology, and by illustrations so characteristic, that they 
may be recognized by ‘“‘any person of ordinary information.”’ This will certainly 
meet and stimulate the growing interest in trees, a purpose that is worth while. 
The authors are in an exceptionally favorable position to make such a book 
accurate rather than merely popular, and it is a good thing now and then for men — 
who have the facts to give to the public something that can be relied upon. The 
identification of trees should now be as easy as the long popular identification of 
birds. The characters are drawn from foliage, flowers, and fruit, and they are pre- — 
sented in the free style of ordinary description, rather than in the compact style of 
taxonomy. The illustrations are from excellent sketches and photographs, and 
really illustrate. The economic value of the various trees is included, so that when 
the name of a tree is discovered, the inquirer is in a position to obtain much useful 
and interesting information concerning it. Of course any definition of a tree must 
be arbitrary, but the authors have liberally included all species known to become 
trees in habit (with “single erect stem or trunk ”), even if they are almost always 
shrubs.—J. M. C. 
MINOR NOTICES 
Physiology of stomata.—Ltovp has given us a careful study of the behavior 
of the stomata in two desert plants, Fouguieria splendens and Verbena ciliata, 
made at the Desert Botanical Laboratory of the Carnegie Institution.’ He 
addressed himself particularly to the question of the regulation of transpiration — 
by stomatal movements, and furnishes conclusive evidence that the stomata it 
these plants, where there are no complications in the way of pits, plugs, or other 
contrivances, are not able to adjust the transpiration to the “‘needs” of the plants. 
Wide variation in the rate of transpiration is found, quite independent of the S 
5 Bot. GAzETTE 392301. Ig05. 
6 BRITTON, NATHANIEL Lorp, and SHareR, JOHN ApotpH, North American 3 
— being descriptions and illustrations of the trees growing independently of cult 
vation in North America, north of Mexico and the West Indies. Imp. 8vo. pp- * + 
894. figs. 781. New York: Henry Holt and Company. 1908. .00. 
‘ 7 Luoyp, F. E., The physiology of stomata. Imp. 8vo. pp. 142. pls. 14. Ags 3% 
Washington: The Carnegie Institution, Publication 82. 1908. a 
