TO HORSE-HEAD CROSSING. 
93 
began to manifest their sufferings in the most piteous 
cries. 
A march of twelve miles brought us to the river 
Pecos, on the banks of which, near the Horse-head 
Crossing, we encamped. 
This river, which is the largest tributary of the 
Rio Grande, is here about 100 feet in width, and in 
the deepest part has four feet of water. Unlike all 
the other streams we had passed, the Pecos has not a 
single tree or shrub along its banks to mark its course, 
nor has it any valley or bottom land near. It runs 
wdth a dark rapid current between high perpendicu- 
lar banks, cut through various strata of clay and sand. 
On both sides is a vast open prairie, entirely destitute 
of trees, though scantily covered with mezquit chap- 
poral, and other plants of the desert. The soil is clay 
and sand, but so blended with saline matter that there 
is no vegetation save the plants mentioned, A few 
rushes grow on the margin of the river; but these 
scarcely appear above its banks, which are here from 
six to ten feet above the water. It is charged with 
an earthy substance, of a reddish or brown hue, which 
imparts its tinge to the water. • As we approached, 
we looked in vain for the usual indications of a 
stream ; for, owing to the want of trees or bushes, it 
was not seen until we were within a few yards of it. 
The Pecos resembles a great canal rather than a 
river. 
During the latter portion of our route we first came 
into the proper chapporal, and met the plants peculiar . 
to the flora of Mexico in such quantities as to give a 
character to the landscape. The term “chapporal,” 
