Chap. VII. THE LITTLE LAGOON. 533 
it you appear to feel nothing. Above and below this 
stratum of clay lie sand and loam. 
We contrived to divide our drove so that each animal 
was led down the height singly to drink. In spite of all 
our efforts to keep back the animals above, thirst made 
them so unruly, that one after another they tumbled over 
the edge of the declivity. When the first fell I thought it 
was irretrievably lost, but to my surprise they all arrived 
below safe and sound. 
We travelled on during the night on an excellent road, 
over a hard argillaceous soil, almost entirely barren, and only 
dotted here and there with some wretched stunted bushes. 
We arrived at the Little Lagoon by two o'clock the next 
morning — a stagnant sheet of water, which only appears 
periodically: at times it does not appear at all for ten 
years together, and then lasts for months, or even years. 
I have already spoken of its rise from the Rio Colorado. 
Not far distant is another temporary lake, called the Great 
Lagoon, which is at times united with the smaller one. 
The country around is a kind of oasis, bare of grass, but 
overgrown with a beautiful grove of algarobbia-trees, 
whose fruit yielded a plentiful repast for our animals. In 
the midst of the Little Lagoon stand mezquite-trees, which 
have died off in the water. Judging from their . size they 
must have attained a growth of full fifteen or twenty years, 
and this without being prevented by water ; consequently, 
at no distant period of time, the lagoon must have been 
continuously dry for that number of years. It must, how- 
ever, have been in existence before that period, as the soil 
contains a collection of the mud of centuries. Hound the 
water lay a circle of thousands of dead fishes ; the water, 
therefore, cannot long have receded from out of the river, 
the fishes having been killed by a gradual and partial 
