our cattle in Arizona and ruined some of our best horses. The Scotch
Company lost many hundreds of cattle by it, and also some horses. The
plant seems to flourish in cycles of about seven years; that is, though
some of it may be present every year it only comes in abundance,
overwhelming abundance, once in the period stated. The peculiarity about
it, too, is that it grows in the winter months and has flowered and
seeded and died down by midsummer. Thus it is the only green and
succulent-looking plant to be seen in winter-time on the brown plains.
It is very conspicuous and in appearance much resembles clover or
alfalfa. Cattle as a rule will avoid it, but for some unknown reason the
time comes when you hear the expression the "cattle are eating loco." If
so they will continue to eat it, to eat nothing else, till it is all
gone; and those eating it will set the example to others, and all that
have eaten it will go stark staring mad and the majority of them die.
Horses are even more liable to take to it, and are affected exactly in
the same way; they go quite crazy, refuse to drink water, cannot be led,
and have a dazed, stupid appearance and a tottering gait, till finally
they decline and die for want of nourishment. I have seen locoed horses
taken up and fed on grain, when some of them recovered and quite got
over the habit even of eating the weed; but these were exceptions. Most
locoed horses remained too stupid to do anything with and were never of
much value. There is one strange fact, however, about them; saddle
horses, slightly locoed, just so bad that they cannot be led, and
therefore useless as saddlers, do, when hitched up to a wagon or buggy,
though never driven before, make splendid work horses. They go like
automatons; will trot if allowed till they fall down, and never balk.
The worst outlaw horse we ever had, one that had thrown all the great
riders of the country and had never been mastered, this absolute
devilish beast got a pretty bad dose of the weed; and, to experiment, we
hitched him up in a wagon, when lo! he went off like any old steady team
horse. This is all very interesting; but that is enough as to its effect
on live stock.

At the request of the Department of Agriculture I sent to Washington
some specimens of a grub which, when the plant reaches its greatest
exuberance and abundance, infests it, eating out its heart and so
killing it. It destroys the plant, but alas! generally too late to
pre