44. NATURE 

ledons, we feel the generic and even the ordinal deter- | 
minations of the fossils to be throughout very doubtful, 
and to be reducible in most cases to the category of bold 
guesses. To refer the majority of living and growing 
monocotyledons, and especially of such orders as Gramz- 
nee, Cyperacee, Naiadee, Palme, and Liliace@, to their 
genera from their leaves alone, is impossible ; much more 
then from the fragmentary fossil remains of these organs. 
Such genera and species, however, have been made, and Dr. 
Schimper must sweep them into his net ; and the more 
ungrateful the task, the more obliged we should be to him 
or performing it so well and so fully. 
We shall look for the Dicotyledonous volume ot this 
great and most useful work with much interest, and lay 
an account of it before our readers as soon as it appears 
J. D. HOOKER 

THE VOSEMITE VALLEY AND THE SIERRA 
NEVADA OF CALIFORNIA 
The Yosemite Guide-book. By J. D. Whitney. Published 
by authority of the Legislature of California. 1869. 
MV R. J. D. WHITNEY, State Geologist of California, 
has prepared a guide-book to the Yosemite Valley 
and the adjacent country, which is a model of its kind. It is 
well written, and is eminently lucid in its descriptions ; it is 
amply illustrated, and has two clear maps on a large scale 
half a mile and two miles to the inch) ; and it is admirably 
printed (at the University Press, Cambridge, U.S.). The 
unpretending title of the work gives but a poor idea of its 
contents ; botanists, geologists, and geographers will find 
pleasure in reading it, although it is ostensibly put forth 
or the sake of the ordinary tourist. It is a valuable con- 
tribution to our knowledge of the Pacific coasts of America, 
and throws light upon a large district which remains very 
imperfectly known. 
The British public has been already tolerably familiar- 
ised with the most striking characteristics of the Yosemite* 
Valley, Mariposa County, California, by the fine picture of 
Mr. Bierstadt ; and some excellent photographs (by Wat- 
kins, of San Francisco), which are now lying before us, 
show that that artist has not drawn upon his imagination. 
Some of our readers, however, may perhaps need to be 
told that it is not only a very remarkable valley, but boasts 
the possession of the highest waterfalls (with an equal 
volume of water) in the world. It is trough-shaped ; a 
cross section of it is like the letter U, and in this respect, 
as well as in its length, breadth, and the steepness of its 
cliffs, it is comparable to the Valley of Lauterbrunnen in 
Switzerland, but the dimensions of its cliffs exceed those 
of that valley, as much as its chief waterfall (the great 
Yosemite Fall) surpasses the Staubbach. This magnifi- 
cent cascade makes a descent of more than half a mile 
in sheer height, and 500,000 cubic feet of water pass 
over it per hour during the month of June. It is made 
up of two falls—an upper one, which has a vertical de- 
scent of 1,500 feet, and a lower one of 4oo feet. The re- 
mainder of the total height is consumed by a series of 
cascades between the two; but seen from the opposite 
side of the valley, the effect is increased rather than 
diminished by the subdivision, and it well deserves all the 
praise which has been lavished upon it. 
* The word Yosemite means a full-grown grisly bear, Zz 

_—@™ es “a! Oe ae | 
[Nov. 17, 1870 
Mr. Whitney does not believe that the peculiar trough 
form of the valley has been even modified by glacier 
action. There are no proofs, he says, “that glaciers have 
ever occupied the valley, or any part of it,” and he scouts 
the notion that it was Aroduced by glacial agency. “In 
short,” he says, “we are led irresistibly to the adoption 
of a theory of the origin of the Yosemite in a way which 
has-hardly yet been recognised as one of those in which 
valleys may be formed, probably for the reason that there 
are so few cases in which such an event can be absolutely 
proved to have occurred. We conceive that during the 
process of upheaval of the Sierra, or possibly at some 
time after that had taken place, there was at the Yosemite 
a subsidence of a limited area, marked by lines of ‘ fault’ 
or fissures crossing each other somewhat nearly at right 
angles. In other and more simple language, the bottom 
of the valley sank down to an unknown depth, owing to 
its support being withdrawn from underneath, during 
some of those convulsive movements which must have 
attended the upheaval of so extensive and elevated a 
chain, no matter how slow we may imagine the process 
to have been.” It should be mentioned that the Yosemite 
Valley is exclusively granite, no remains of sedimentary 
rocks having been found within it. 
Although the Yosemite Valley itself is not ice-ground, 
in its neighbourhood there are very emphatic traces of 
glacial action, and it is said that in some places the 
polish is so perfect upon the rocks, that “the surface 
is often seen from a distance to glitter with the light 
reflected from it, as from a mirror.” It is remarkable 
that no glaciers are known to exist at the present time 
throughout the entire length of the Sierra Nevada in 
California. Throughout the entire region, from 35° to 
42° N. lat., Mr. Whitney asserts that there is not a single 
glacier. Yet Mount Shasta, at the northern extreme, 
with a height of pretty well 15,000 feet, is more or 
less ._permanently covered with snow upon its upper 
6,000 feet, and at the southern end of the district there 
are numerous peaks (now being surveyed) which range 
from 14,000 to 15,000 feet, and even higher. We confess 
that we do not understand how “ masses of snow, several 
miles long, and hundreds of feet in thickness, remain all 
summer without showing any indication of becoming 
glacier ice,” if they remain permanently of these dimen- 
sions; but as such seems to be the fact, there is no use 
in disputing it. 
The most valuable portions of Mr. Whitney’s book are 
those which he has devoted to elucidating the topography 
of the mountain ranges bordering upon, or in proximity 
to, the Pacific Coast. We learn from him in a clearer 
way than we have seen it put before, that there are two 
great ranges of mountains running throughout the length 
of California, which are orographically distinct. These he 
terms the Coast Ranges, andthe Sierra Nevada. Theyare 
roughly parallel to each other, and tothe coast line ; and they 
are divided by the valleys of the Sacramento and San Joa- 
quin rivers. The coast ranges are, geologically speaking, 
younger than the Sierra Nevada, and they are chiefly 
made up of cretaceous and tertiary strata. They are also 
of comparatively small elevation, and their highest sum- 
mits attain only 8,000 feet. The core of the Sierra Nevada, 
on the other hand, is mainly granitic, flanked on both sides 
by metamorphic slates, and has a much greater elevation. 
3 
