ADMINISTRATIVE REPORT LVII 
keys skirting the coast have been greatly modified and even 
extended artificially, the shell accumulations with accompa- 
nying débris in some instances covering many acres, and in 
certain cases reaching a depth of several yards. Locally the 
shell accumulations have evidently been made with definite 
purpose, and have been carried up symmetrically into large 
mounds comparable in dimensions with the Indian mounds 
of the interior. In his studies of the Seminole Indians, Mr 
Cushing found that they display certain characteristics which 
appear to ally them with the Caribs. One of these is the 
custom of living in pile dwellings under certain circumstances; 
and pile dwellings now occupied, as well as some structures 
now abandoned, and others of considerable antiquity were 
examined. Some of these pile dwellings appeared to Mr 
Cushing to stand in definite relation to certain of the shell 
mounds, particularly those of definite form, and through this 
relation he is able to gain some insight into the origin and 
development of mound building among the American aborigi- 
nes, this insight being in part due to his intimate acquaint- 
ance with Indian modes of thought. 
He finds that, in the interests of convenience, a pile dwell- 
ing is located over the waters of a sound, perhaps some yards 
from the shore; but while yet occupied by the builders, the 
domestic débris (chiefly refuse shells) accumulates until it rises 
above the water level, when the building appears to stand on 
posts in a low mound. Now the Indian is curiously persistent 
in habit, so that the men of the second generation who chance 
not to be constrained otherwise by environment, regard the 
pile-mound structure as normal and proper and worthy of imi- 
tation. As time passes, the accumulation beneath and about 
the original house goes on until the piles are buried and the 
habitation stands on a mound, when in turn this type of strue- 
ture comes to be regarded as the normal and proper type 
among the younger and more active members of the tribe just 
beginning house construction. Through this natural series of 
changes in type of habitation and in concert, and through the 
myth-constrained social organization of the people, there is a 
tendency to the development, under favorable circumstances, 
