744 THE CRANIA OF THE MOUND-BUILDERS. 
singular conformation of head, being without forehead, the crania 
retreating backward immediately above the superciliary arch. 
This anomaly, which is generally ascribed to an artificial disfigura- 
tion of the head or taste of the artist, now admits of a more 
natural explanation, it being proved by these authentic documents, 
that there really existed in this country a race exhibiting this 
anomalous conformation. The skeletons which were of both sexes, 
were of the ordinary height, although two of them were above 
the common stature. These heads according to the received 
opinion in Craniology, could not have occupied a high position 
intellectually.” * 
Rivero and Tschudi, whose researches in South America com- 
mand confidence, believe that the artificial disfigurement of the 
skull which prevailed amongst the Inca-Peruvians owed its origin 
to the prior existence of an autochthonous race having this pecu- 
liarity ; and they further state that it is in some instances 
congenital, as it is seen in the foetus of Peruvian mummies. 
In the Peruvian skull figured by Tiedemann, this peculiarity is 
also represented. ee 
hese authorities would indicate that there was a conformity in 
the craniology of the earlier races on this hemisphere, embracing 
the primeval people of Brazil, the platform-builders of Peru and 
Mexico, and the mound-builders of the Mississippi Valley. 
The Peruvian skull, as compared with the Indian, is deficient in 
capacity being, according to Morton, no greater than that of the 
Hottentot or New Hollander. In measuring 155 crania of the for- 
mer, they gave but 75 cubic inches for the bulk of ‘the brain, while 
the Teutonic crania gave 92 inches. The average difference be- 
tween the Peruvian and Indian is 9 inches in favor of the latter. t 
How is it then, it has been asked, that with this low mental pow- 
er, these Peruvians should have been able to construct such stupen- 
dous works, and develop a very considerable civilization, while 
the Indian, with far greater volume of brain, exhibits such slight 
constructive power and has resisted all attempts to elevate his — 
condition? Mr. J. S. Phillips has attempted to answer this ques- 
tion: - 
“The intellectual lobe of the brain of these people, if not borne 
own h overpowering animal propensities and passions, 
_ would, doubtless, have been capable of much greater efforts than 
any-with which we are acquainted, and have enabled these barbarie 
tribes to make some progress in civilization. * * The m 
* Jour. Acad. Nat. Sci. Phila., 1844. t Morton’s “ Crania Americana.” 
