umpkins. All three are
preeminently summer crops and need much water in July and August. In
California there is no rain at this season. Though the fall rains, which
begin to be abundant in October and November, do not aid these
summer crops, they favor wheat and barley. The winter rains and the
comparatively warm winter weather permit these grains to grow slowly but
continuously. When the warm spring arrives, there is still enough rain
to permit wheat and barley to make a rapid growth and to mature their
seeds long before the long, dry summer begins. The comparatively dry
weather of May and June is just what these cereals need to ripen the
crop, but it is fatal to any kind of agriculture which depends on summer
rain.

Crops can of course be grown during the summer in California by means of
irrigation, but this is rarely a simple process. If irrigation is to
be effective in California, it cannot depend on the small streams which
practically dry up during the long, rainless summer, but it must depend
on comparatively large streams which flow in well-defined channels. With
our modern knowledge and machinery it is easy for us to make canals and
ditches and to prepare the level fields needed to utilize this water. A
people with no knowledge of agriculture, however, and with no iron tools
cannot suddenly begin to practice a complex and highly developed system
of agriculture. In California there is little or none of the natural
summer irrigation which, in certain parts of America, appears to have
been the most important factor leading to the first steps in tilling the
ground. The lower Colorado, however, floods broad areas every summer.
Here, as on the Nile, the retiring floods leave the land so moist
that crops can easily be raised. Hence the Mohave Indians were able to
practice agriculture and to rise well above their kinsmen not only in
Lower California but throughout the whole State.

In the Rocky Mountain region of the United States, just as on the
Pacific coast, the condition of the tribes deteriorated more and more
the farther they lived to the south. In the regions where the rainfall
comes in summer, however, and hence favors primitive agriculture, there
was a marked improvement. The Kutenai tribes lived near the corner where
Idaho, Montana, and British Columbia now meet. They appear to have
been of rather high grade, noteworthy for their morality, kindness, and
hospitality. More than any other Indians of the Rocky Mo