tone age which are found in the northern part of the
Main island are usually attributed to the Ainos. These remains have been
collected and studied both by native scholars and by foreigners. Among the
most important of them have been the articles found in shell heaps
uncovered in different parts of the empire. The first(20) to which foreign
attention was drawn was that at Omori, near Tokyo. Since then many others
have been opened and many valuable finds have been reported. The shell
heaps have evidently been used like kitchen-middens in Europe and
elsewhere, as places for dumping the refuse of shell-fish used for food.
These became places for the throwing of useless and broken articles used
in the household, and thus have been the means of preserving many of the
implements used in prehistoric times. The most significant discovery made
in these shell heaps was that at Omori, of the bones of human beings
artificially broken in such a way as to indicate that cannibalism had been
prevalent at the time. Whether this can be assumed as sufficient proof of
so grave a charge has been disputed. It is claimed(21) that in at least
seven similar shell heaps no human bones and no evidences of cannibalism
were found. If however the case is considered as sufficiently proved, it
is clear from this as well as from many other circumstances that the Ainos
of that early day were by no means the mild and gentle race which we now
find them. It is interesting to note that Marco Polo(22) mentions
cannibalism as one of the customs which were believed to exist in Japan in
his day.

Besides the Ainos there is evidence of the existence of another savage
tribe, which at an early date seems to have been found in many parts of
the Main island, and at a later date in the island of Yezo and the Kurile
islands on the north. They are the so-called pit-dwellers. In the very
earliest writings of the Japanese we find references to them. They dug
pits in the earth and built over them a roof, and used these pits or
cellars as rooms in which to sleep. The Japanese conquerors in the central
parts of the Main island had many conflicts with these pit-dwellers. And
in the north and east they as well as the Ainos were encountered by the
military forces of the empire. They were probably driven north by the more
powerful Ainos and have almost disappeared. Abundant evidence(23) however
is found in the island of Yezo of their previous existence. The Ainos in
their tradit