THE BOTANY OF THE CUYAMACA MOUNTAINS. 97 
slope is too subject to the parching east or “ Desert” winds to be of 
much value for any but mining purposes. From here the descent 
toward the northwest is very rapid, and pines end all at once ; oaks, 
however, continuing on the north slopes and in moist spots. The 
Quercus agrifolia becomes again more common than the Quercus 
crassipocula which ceases at about six hundred feet. On the east 
slope it will be noticed that the zone of oaks is entirely wanting, 
or is mingled with that of pines, while the cactus zone immediately 
succeeds them. 
Here the Cuyamaca range ends, being separated from other 
ranges to the north and northeast by the Pass and by Santa Isabel 
valley at the head of San Bernardo river. Its length, from this to 
the railroad pass near the Mexican Boundary, is thus about twenty- 
five miles, its width about the same, leaving out the low foot-hills 
on the west, and including only the portion above an elevation of 
two thousand feet. Descending into the valley, the sycamore re- 
appears at about three thousand eight hundred feet, the cottonwood 
at three thousand five hundred feet, and the black oak disappears 
at the same elevation. The country is more cut up by wide valleys 
than on the slope we ascended, but they are generally drier at the 
same altitude. At our camp in anarrow valley, one thousand eight 
hundred and fifty feet high, trees were scarce, and crops grew only 
by irrigation. 
May Ist. The road led over a rolling granitic ridge of hills be- 
tween the San Bernardo and San Diego rivers, with scanty herb- 
age and scattered oak groves, to the north side of Cajon valley, 
where we looked down from about one thousand feet elevation over 
this curious basin six hundred feet below us, and also over the 
terraced mésa toward the ocean, plainly perceiving San Clemente 
island eighty-five miles distant. The ‘‘ Desert wind,” which com- 
menced yesterday, made the air unusually clear, but at the same 
time was so hot and dry as to be very uncomfortable. The Cuya- 
maca peaks appeared now to be completely bare of snow. 
As the rest of the journey back was over the same route before 
described, I omit farther extracts from my journal. It must appear 
from these notes that this range, from its liability to severe 
droughts, does not have such a luxuriant flora and sylva as might 
-be expected from its southern position, the trees being all merely 
o _ Stragglers from more northern forests, and none of them, except 
: the yellow pine and oaks, found in great abundance. At the same 
| AMER. NATURALIST, VOL. VIL 
