Chap. IV. LAYERS OF CONGLOMERATE. 491 
tolerably well, and had a certain dignified demeanour. On 
my expressing, in conversation with him, a certain mistrust 
of his assurances of friendship, he raised his hands and eyes 
towards the sun, and said, " Do you not believe that God — 
this Sun — {que Dios, este sol) — sees what we do, and 
punishes us when it is evil." The expression interested me 
much ; and yet I should not willingly have trusted my 
life to the sanctity of the oath. This troop was known 
in the villages of Sonora by the name of the Biscainos, 
which means, " from the State of Chihuahua," as this 
latter was formerly known by the name of New Biscay. 
The continuation of the journey led us through a 
charming little valley, with rocks on each side, and with a 
clear rivulet running through it. Shady oaks grew at the 
foot of the rocks, and a few old poplars on the edge of the 
brook. The higher mountains in the background consist 
of porphyry, rising in pointed forms. But between these 
eruptive formations, strata of a coarse conglomerate are 
found in the valley, in their original horizontal position, 
and apparently belonging to the causes of the great number 
and peculiar arrangement of springs in this region. This 
formation appears to be very extensive, spreading far into 
Sonora ; but only filling up valleys between eruptive masses, 
and perhaps itself an accessory product of the eruption, 
especially of the granite found here likewise. 
The main road, from which we nowhere saw any other 
route branch off, led us straight toward a steep mountain, 
and into a defile full of clefts, which reminded us of the 
Guadalupe Pass. The ground was covered with oak- 
wood. The road became more and more difficult, and at 
last impassable ; nothing remained but to return to the 
plain. 
We were not far from Santa Cruz, the first inhabited 
