1900 | CURRENT LITERATURE 359 
school. The rearrangement of the laboratory work is particularly commend- 
able. The logical arrangement, clear treatment, and freshness of the larger 
book are retained in this volume. There is still left a heavy year’s work for 
a good teacher and a strong class, and it is the judgment of the reviewer 
that further simplification might have been secured by the less minute treat- 
ment of some subjects, as the root, movement of plants, growth, and ecology, 
admirable as those subjects are in their present form. The many good 
points of the book will commend it to secondary teachers, whose class room 
experience alone can determine its fitness to survive-—I. N. MITCHELL, 
State Normal School, Milwaukee, Wis. 
The white pine.° 
THE white pine has always commanded more than its share of study 
because of its economic importance. In so far as Professor Spalding and Dr. 
Fernow have succeeded in explaining the geographic and edaphic factors 
which control its distribution, they have made a valuable contribution to 
ecology and plant geography. The large number of acre-yield tables of 
measurements and explanations of soil and forest conditions enable them to 
draw certain definite and scientific conclusions regarding the causes of dis- 
tribution. 
The leading ecological factor is the nature of the soil and the water con- 
tent of the same. While adapting itself to almost any variety of soil, the 
white pine prefers one with a fair admixture of sand, insuring a moderately 
rapid drainage. This is a soil intermediate between the stiff clayey soil on 
one hand, where the deciduous forest predominates, and the dry, light sandy, 
Coarse and gravelly soil on the other hand, where the red pine (Pius resi- 
nosa) and the jack pine (Pinus Banksiana) seem able to outdo it. The 
shallow root system of the white pine permits it to occupy the thinner soils of 
the rocky slopes in the Adirondacks and New England states. 
Light is another important ecological factor. Compared with other pines 
the white pine has great shade endurance, hence its admixture with maples 
and beech, where it has an equal chance in open places. But white pine 
Seedlings are never found in the dense shade of the hardwood forest Fe 
such a place there is little hope for the white pine to gain a foothold. Owing 
‘0 this inability of the white pine seedling to maintain itself in the dense 
shade, the hardwood forest is gradually encroaching upon it, except in soils 
too poor for the development of the deciduous forest. 
_ A carefully prepared map of the geographic distribution 0 
Non for the discussion of the climatic factors governing such 
ffers a founda- 
distribution. 
*SPALDING, V. M.: The white pine. Revised and enlarged by B. E. FERNOW. 
Contributions on insect enemies of the white pine by F. H. CHITTENDEN, and on the 
ey of the white pine by FILIBERT RoTH. Bulletin no. 22. U. S. Department of 
Sticulture, Division of Forestry. gto. pp. 185. #7. —. 1899. 
