HO Floristik, Geographie, Systematik etc. 



environment. They include the influence of climate, soil, physio- 

 graphy, chronologj'^ and the life relations of the surroundings. The 

 influence of these conditions on the richness of floras may be con- 

 sidered statistically. The generic coefficient, which is the relativity 

 of genera and species, is inversely proportional to the diversity of 

 the ecologic conditions. The generic coefficient was worked out for 

 the floras of Point Pelee, Ontario; for the pine-barrens of New 

 Jersey; for Hartsville, South Carolina; for the Alabama 

 Grit Region of Georgia; for Miami, Florida; for the Florida 

 Keys; for the Upper Susquehanna, Pennsylvania; for Lan- 

 caster County, Pennsylvania; for Columbia, Missouri; 

 for Jackson County, Missouri; for the Yosemite National 

 Park, California; for the State of Connecticut; for the State 

 of Pennsylvania; for Alabama; for the central Rocky Moun- 

 tains; for the State of Washington. It was found that Point 

 Pelee with a simple topography was at one extreme with a gene- 

 ric coefficient of 74,7 per cent; and the Central Rocky Moun- 

 tains, and the Southeastern United States at the other extreme 

 with highly diversified and generic coefficients of 23,9 per cent 

 and 23 per cent respectively. Harshberger. 



Howe, C. D. and J. H. White. Trent Watershed Survey. 

 (Canadian Commission of Conservation, Committee on Forests. 

 Toronto 1913.) 



This report of 153 pp. with maps and illustrative plates with 

 an introduction by B. E. Fernow deals with the forests of a por- 

 tion of the watershed of the Trent Canal, situated in Hastings, 

 Peterbor ough, Haliburton, and Victoria counties, On- 

 tario. The report considers the drainage, topography, geology 

 soils and the condition of the various forest types. Harshberger. 



Illick, J. S., American Trees in German Forests. (Amer. 

 Forestry. XXI. p. 922-927. Sept. 1915.) 



Observations are given regarding the growth of the following 

 trees in German forests: arbor-vitae (introduced in 1566), bald cy- 

 press (1640), tulip tree (1663), red cedar (1664), baisam fir (1697), 

 white and black spruces (1700), white pine (1705) and at later dates 

 the black locust, red oak, cottonwood, black walnut, black cherry, 

 shellbark, hickory, Douglas fir, Sitka spruce and Sequoia. The illu- 

 strations show a number of American trees in German forests. 



Harshberger. 



&" 



Illick, J. S., Pennsylvania Trees. (Bull. 11, Penns. Dept. Fo- 

 restry. June 1914.) 



This finely illustrated book deals in the first 50 pp. with the 

 forests and forestry of Pennsylvania, the structure of the forest,, 

 its establishment, its development and its protection. These pages 

 also consider the value of trees and forests. deciduous and ever- 

 green trees, the age of trees, the form and structure of trees. 

 Pages 53 to 223, constituting Part II of the book, are concerned 

 with the identification, tabulation and description of the species. 

 Each species is illustrated by a drawing of leaves, flowers, fruit 



