nd there
deepens into green of the richest--a plain token of moisture in the
hollows--a blessing indeed in this dry weather. In the far West and
Northwest the buffalo grass has often to contend with drought for months
together, so that it has learned to strike deep in quest of water to
quench its thirst. It is a by-word among the ranchmen that the roots go
clear through the earth and are clinched as they sprout from the ground
in China. Joking apart, they have been found sixty-eight feet below the
surface of the prairie, and often in especially dry seasons cattle would
perish were not these faithful little well-diggers and pumpers
constantly at work for them. In the river valleys of Arizona although
the air is dry the subsoil water is near the surface of the ground. Here
flourishes the mesquit tree, _Prosopis juliflora_, with a tale to tell
well worth knowing. When a mesquit seems stunted, it is because its
strength is withdrawn for the task of delving to find water; where a
tree grows tall with goodly branches, it betokens success in reaching
moisture close at hand. Thus in shrewdly reading the landscape a
prospector can choose the spot where with least trouble he can sink his
well. And plants discover provender in the soil as well as drink. Nearer
home than Arizona we have only to dislodge a beach pea from the ground
to see how far in search of food its roots have dug amid barren stones
and pebbles. Often one finds a plant hardly a foot high with roots
extending eight feet from its stem.

And beyond the beaches where the beach peas dig so diligently are the
seaweeds--with a talent for picking and choosing all their own. Dr.
Julius Sachs, a leading German botanist, believes that the parts of
plants owe their form, as crystals do, to their peculiarities of
substance; that just as salt crystallizes in one shape and sugar in
another, so a seaweed or a tulip is moulded by the character of its
juices. Something certainly of the crystal's faculty for picking out
particles akin to itself, and building with them, is shown by the kelp
which attracts from the ocean both iodine and bromine--often dissolved
though they are in a million times their bulk of sea water. This trait
of choosing this or that dish from the feast afforded by sea or soil or
air is not peculiar to the seaweeds; every plant displays it. Beech
trees love to grow on limestone and thus declare to the explorer the
limestone ridge he seeks. In the Horn silver mine