DEPARTMENT OF BOTANY 
THE OHIO STATE UNIVERSITY 
w - °- THOMPSON, PHESTDEKT 
J. H. SCHAFFNEE 
R. F. GRIGGS 
W. G. STOVER 
FREDA DETMERS 
H. C. SAMPSON 
P. B. SEARS 
A. E. WALLER 
GOLUMBUS 
May 10, 1919. 
Professor M. L. Fernald, 
Gray Herbarium, 
Cambridge, Mass. 
Pear Professor Fernald: 
In reading over your recent paper on the "Ranges of Pinus & Thuja" 
I note your characteristic remarks about a map which I published some fifteen years 
ago. I went back to the paper and I am still wondering where you found the statement 
that I thought the areas within the boundaries given for Pinus Banksiana are 
"dominated" by this pine. I also wonder whether you realize the difficulties that 
attended the securing of exact data for the making of the maps at that time. I recall • 
writing to the Gray Herbarium the year before that paper was published for data 
concerning the distribution of a short list of trees and shrubs. The letter was never 
answered, although a similar inquiry to the Canadian Herbarium brought a prompt 
response, I can't help feeling that you understood the typographical error which 
occurs in Hutchinson's paper "Abies canadensis" quite as well as I understood what 
you meant in your paper by "Casianea dentata". Very few papers are printed that are 
entirely free from such blunders. 
Personally, I have been much interested in the few distribution 
papers you have published and have wished that they were multiplied in number. You 
are certainly wrong in assuming that all the botanists interested in ecology are 
disinterested in accuracy of species names or are willfully neglecting the chemical 
factors in plant distribution. 
To take the specific case mentioned in your paper: I have known for 
a long time that Thuja is practically confined to limestone cliffs and alkaline bogs 
in Ohio. This explanation however does not account for its absence over large areas 
in the middle west where these same soil conditions occur. In my paper on the 
"Forest Centers" I was trying to account for the factors which relegated large bodies 
of olants to the Northeastern Evergreen Forest and others to the Deciduous forest, 
and I still believe these are competes of climatic factors. Within any of these 
great centers I should account for the local occurrence of particular species on the 
basis of soil factors, including acidity alkalinity, etc. 
It may be of interest to you to know that the western most station for 
Castanea dentata in Ohio is on limestone cliffs associated with Quercus Muhlenbegif 
although this is usually found on sandstone outcrops. There is physiological evidence 
that calcium retards absorption of water and I have wondered just how much this is 
of importance in explaining the distribution of "calciphiles" and "calciphobes". 
It seems to me that is most unfortunate when so much remains to be 
done toward explaining the distribution of plant association in North America that so 
much space should be used in acrimonious rather than in presenting 
evidence, upon which any hypothesis of plant distribution must stand or fall. 
