PREFACE. Vil 
life in these periods is indispensable to a definite conception of the stages 
of human progress. From the laws which govern this progress, from the 
uniformity of their operation, and from the necessary limitations of the prin- 
ciple of intelligence, we may conclude that our own remote ancestors passed 
through a similar experience and possessed very similar institutions. In 
studying the condition of the Indian tribes in these periods we may recover 
some portion of the lost history of our own race. This consideration lends 
incentive to the investigation. 
The first chapter is a condensation of four in ‘Ancient Society,” 
namely, those on the gens, phratry, tribe, and confederacy of tribes. As 
they formed a necessary part of that work, they become equally necessary 
to this. A knowledge of these organizations is indispensable to an under- 
standing of the house life of the aborigines. These organizations form the 
basis of American ethnology. Although the discussion falls short of a com- 
plete explanation of their character and of their prevalence, it will give the 
reader a general idea of the organization of society among them. 
We are too apt to look upon the condition of savage and of barbarous 
tribes as standing on the same plane with respect to advancement. They 
should be carefully distinguished as dissimilar conditions of progress. 
Moreover, savagery shows stages of culture and of progress, and the same 
is true of barbarism. It will greatly facilitate the study of the facts re- 
lating to these two conditions, through which mankind have passed in their 
progress to civilization, to discriminate between ethnical periods, or stages 
of culture both in savagery and in barbarism. The progress of mankind 
from their primitive condition to civilization has been marked and eventful. 
Each great stage of progress is connected, more or less directly, with some 
important invention or discovery which materially influenced human prog- 
ress, and inaugurated an improved condition. For these reasons the period 
of savagery has been divided into three subperiods, and that of barba- 
rism also into three; the latter of which are chiefly important in their rela- 
tion to the condition of the Indian tribes. The Older Period of barbarism, 
which commences with the introduction of the art of pottery, and the Middle 
Period, which commences with the use of adobe brick in the construction 
of houses, and with the cultivation of maize and plants by irrigation, mark 
