February, the grove or plantation at the estancia house, with its deep
fresh unchanging verdure and shade, was a veritable refuge on the vast
flat yellow earth. It was then, when the water-courses were gradually
drying up and the thirsty days coming to flocks and herds, that the
mocking illusion of the mirage was constantly about us. Quite early in
spring, on any warm cloudless day, this water-mirage was visible, and
was like the appearance on a hot summer's day of the atmosphere in
England when the air near the surface becomes visible, when one sees
it dancing before one's eyes, like thin wavering and ascending tongues
of flame--crystal-clear flames mixed with flames of a faint pearly or
silver grey. On the level and hotter pampas this appearance is
intensified, and the faintly visible wavering flames change to an
appearance of lakelets or sheets of water looking as if ruffled by the
wind and shining like molten silver in the sun. The resemblance to
water is increased when there are groves and buildings on the horizon,
which look like dark blue islands or banks in the distance, while the
cattle and horses feeding not far from the spectator appear to be
wading knee or belly deep in the brilliant water.

The aspect of the plain was different in what was called a "thistle
year," when the giant thistles, which usually occupied definite areas
or grew in isolated patches, suddenly sprang up everywhere, and for a
season covered most of the land. In these luxuriant years the plants
grew as thick as sedges and bulrushes in their beds, and were taller
than usual, attaining a height of about ten feet. The wonder was to
see a plant which throws out leaves as large as those of the rhubarb,
with its stems so close together as to be almost touching. Standing
among the thistles in the growing season one could in a sense _hear_
them growing, as the huge leaves freed themselves with a jerk from a
cramped position, producing a crackling sound. It was like the