166 ERYTHEA. 
parts of which were embedded in drift from ten to thirty 
feet deep. An artesian well was then being bored at the 
mole in Oakland. At two hundred feet below the surface a 
redwood log was encountered. These are very substantial 
hints of a very ancient history of this patch of forest over- 
looking Oakland and now so nearly extinct; and the half 
denuded slopes, the dark cafions still untraversed by either 
botanist or geologist, and the hidden depths over which we 
build securely our villages and cities hold records yet to be 
unfolded. 
THE VEGETATION OF THE SUMMIT OF 
MOUNT DIABLO. 
By Epwarp L. GREENE. 
As seen from the northward, and all around to the south- 
eastward, Mount Diablo is a darkly outlined but imposing 
pyramid rising quite abruptly from the western side of the 
plains of the lower Sacramento and San Joaquin rivers. It 
is the chief landmark to residents within and _ travelers 
through the great interior valley of middle California. It 
is also the culminating point of the inner Coast Range 
in the latitude of San Francisco. Its summit, according to 
the best of authorities, Dr. George Davidson of the U. 8. 
Coast and Geodetic Survey, has an altitude of 38484 feet. 
Its nearest neighbor in the same range of hills, Mount 
Hamilton,! is 40} miles distant a little east of southward, 
and is some 360 feet higher. 
The climatic differences between Mt. Diablo and Mt. 
Hamilton must needs be considerable. The peak last named, 
besides being much farther inland, is separated from the 
ocean by the Santa Cruz Mountains, an elevated section of 
\For a sketch of the Botany of Mt. Hamilton see pages 77—97 of this 
volume. 
