[Reprinted from Ruopora, Vol. 21, No. 243, March, 1919.] 
CONTRIBUTIONS FROM THE GRAY HERBARIUM 
OF HARVARD UNIVERSITY. 
‘ ; } 
J 
New Series.— No. LVIII. 
Litno.ocicaL Factors LIMITING THE RaNGEs or Pinus BANKSIANA AND 
THUJA OCCIDENTALIS. : 
M. L. Fernap.. 
