It is probable that the successive arts of subsistence which arose at long intervals will ultimately, from the great influence they must have exercised upon the condition of mankind, afford the most satisfactory bases for these divisions. But investigation has not been carried far enough in this direction to yield the necessary information. With our present knowledge the main result can be attained by selecting such other inventions or discoveries as will afford sufficient tests of progress to characterize the commencement of successive ethnical periods. Even though accepted as provisional, these periods will be found convenient and useful. Each of those about to be proposed will be found to cover a distinct culture, and to represent a particular mode of life. The period of savagery, of the early part of which very little is known, may be divided, provisionally, into three sub-periods. These may be named respectively the _Older_, the _Middle_, and the _Later_ period of savagery; and the condition of society in each, respectively, may be distinguished as the _Lower_, the _Middle_, and the _Upper Status_ of savagery. In like manner, the period of barbarism divides naturally into three sub-periods, which will be called, respectively, the _Older_, the _Middle_, and the _Later_ period of barbarism; and the condition of society in each, respectively, will be distinguished as the _Lower_, the _Middle_, and the _Upper Status_ of barbarism. It is difficult, if not impossible, to find such tests of progress to mark the commencement of these several periods as will be found absolute in their application, and without exceptions upon all the continents. Neither is it necessary, for the purpose in hand, that exceptions should not exist. It will be sufficient if the principal tribes of mankind can be classified, according to the degree of their relative progress, into conditions which can be recognized as distinct. I. _Lower Status of Savagery._ This period commenced with the infancy of the human race, and may be said to have ended with the acquisition of a fish subsistence and of a knowledge of the use of fire. Mankind were then living in their original restricted habitat, and subsisting upon fruits and nuts. The commencement of articulate speech belongs to this period. No exemplification of tribes of mankind in this condition remained to the historical period. II. _Middle Status of Savagery._ It commenced with the acquisition of a fish subsistence and a knowledge of the use of fire, and ended with the invention of the bow and arrow. Mankind, while in this condition, spread from their original habitat over the greater portion of the earth’s surface. Among tribes still existing it will leave in the Middle Status of savagery, for example, the Australians and the greater part of the Polynesians when discovered. It will be sufficient to give one or more exemplifications of each status. III. _Upper Status of Savagery._