189] ENGELMANN—REVISION OF THE GENUS PINUS, ETC. 29 
botanical gardens and the curators or possessors of the great her- 
baria, who most liberally furnished me with the material to carry 
on my investigations of the Pines and of the Conifers in general. 
I am particularly indebted to Messrs. Bolander, Brewer, Parry 
and Lemmon for their contributions of the Californian and Rocky 
Mountain Conifers, and to Messrs. Canby, Gilman, Ravenel and 
Mellichamp for those of the northern and eastern American 
ines. 
