A. G. Tansley. 
this region by a number of very closely allied species difficult to 
discriminate— Cercocarpus, Ceanothus , etc., which together form the 
dense scrub, the true Californian chaparral. Among the chaparral 
are seen scattered trees of Pinus sabiniana —the Digger Pine—a 
light loose-foliaged pine with very heavy massive cones accompanied 
by another evergreen oak, Quercus chrysolepis, a small tree generally 
12 or 15 feet high with somewhat contorted branches and the under¬ 
sides of the leaves covered with close-set golden scale-like hairs. 
Q. Kelloggii, a deciduous “black” oak, and Q. Wislizeni, a small 
dark-leaved evergreen oak, also appear. The whole aspect of the 
vegetation of this valley is decidedly mediterranean. The chaparral 
growth-forms strongly resemble those of mediterranean maquis, 
while Pinus sabiniana recalls the mediterranean P. halepensis, and 
the evergreen oaks correspond with Q. Ilex and Q. suber, though 
the American species are far more numerous. Pinus ponderosa 
begins to appear as single trees, though at this level—less than 
2,000 feet—only small isolated trees occur. Libocednis decurrens 
also begins to appear. In the evening El Portal—the terminus of 
the line and the gate of the Yosemite region, dominated by the steep 
and lofty hills which here shut in the canyon of the Merced river— 
was reached. 
On the following morning—September 8th—the party continued 
the journey up the Merced canyon in horse-drawn vehicles. Pinus 
sabiniana and Quercus Wislizeni begin to disappear; Pinus ponderosa 
increases; Pseudotsuga, though not in quantity, begins to put in an 
appearance; and among other interesting trees and shrubs met with 
are the rare “Californian nutmeg” {Torreya californica), JEsculus 
californica, Rhamnus californicus, Rhododendron californicum (deci¬ 
duous) and the strongly aromatic “Californian laurel” ( Umbellularia 
californica). 
The entrance to the Yosemite valley is flanked by the truly 
magnificent El Capitan rock, a practically vertical wall of granite 
3,000 feet high. The valley itself is a canyon or trough with a flat 
alluvial floor and nearly vertical walls varying from 2,000 to 4,000 
feet in height. The floor is still largely park-like with open stretches 
of grass alternating with stands of trees— Pinus ponderosa , P. 
Murrayana , Libocednis decurrens , Quercus Kelloggii. The park-like 
character of the vegetation is due to the annual fires started by the 
Indians which kept down the forest growth. Since the district has 
passed under American control, these fires no longer occur and dense 
young stands of the conifers are springing up. The south-facing side 
of the valley bears Pinus ponderosa on the rocks and in ravines, and 
