76 Professor D. Wilson’s Illustrations of the Significance 
67 to 70 per cent. It is obvious, therefore, that under the 
peculiar physiological condition of the cranial bones during 
the period of nursing, such constant mechanical action as 
the occiput of the Indian pappoose is subjected to must be 
productive of permanent change. The child is not removed 
from the cradle-board when sucking, and is not therefore 
liable to any counteracting lateral pressure against its 
mother’s breast. One effect of such continuous pressure 
must be to bring the edges of the bones together, and 
thereby to retard or arrest the growth of the bone in certain 
directions. The result of this is apparent in the premature 
ossification of the sutures of artificially deformed crania. 
At Washington I had an opportunity of minutely exa- 
mining thirty-four Flathead skulls brought home by the 
United States Exploring Expedition, some of them pre- 
senting the most diverse forms of distortion. In the ma- 
jority of those, the premature ossification of the sutures is 
apparent, and in some they are almost entirely obliterated. 
The same is no less obvious among the corresponding class 
in the collection of the Academy of Natural Sciences of 
Philadelphia, and especially in skulls of the Chinooks, who 
carry the process of deformation to the greatest extent. 
But I have also been struck, not only with the frequent 
occurrence of wormian bones in such altered skulls, but also 
with the distinct definition of a true supraoccipital bone. 
It is marvellous to see the extraordinary amount of dis- 
tortion to which the skull and brain may be subjected 
without seemingly affecting either health or intellect. The 
coveted deformity is produced partly by actual compression, 
and partly by the growth of the brain and skull being 
thereby limited to certain directions. Hales, the eth- 
nographer of the exploring expedition, after describing the | 
process as practised among the Chinooks, remarks: ‘“‘ The 
appearance of the child when just released from this con- 
finement is truly hideous. The transverse diameter of the 
head above the ears is nearly twice as great as the longi- 
tudinal from the forehead to the occiput. The eyes, which 
are naturally deep set, become protruding, and appear as if 
squeezed partially out of the head.”* Mr Paul Kane, in 
* Ethnography of the U. S. Exploring Expedition, p. 216. 
