698 Dynamic Theory. 



ond classes is assured by the direct action of the environing forces; that 

 of the third class is contingent upon the exertion of these forces through 

 society. It is to combinations of the perceptions of the third class that 

 we owe the development of our ideas of morality and duty. In the or- 

 der of time, therefore, it is obvious that the organs of such ideas are 

 the latest, and they are the most inconstant and uncertain; and in the 

 event of mental disintegration and insanity are usually the first to dis- 

 appear. 



Fia. 373. 



FTG. 373. Heads of the Peruvian race from Yucatan, Mexico. (Nott & Gliddon, Types 

 of Mankind.) In some divisions of this race in Peru, this form of head was natural, in 

 others artificial. (Did art imitate nature in this case, or did the artificial fashion from 

 long usage become hereditary and natural ? ) 



Little experimental proof can be furnished in regard to the location 

 of the organs upon which the purely intellectual states depend. Their 

 growth develops into fissures quite as much, perhaps more than into 

 convolutions, and probably some organs are chiefly in fissures, while 

 others are in convolutions. Some are upon the underside of the hemi- 

 spheres, and some upon their mesial surfaces. It is unreasonable, there- 

 fore, to suppose there can ever be any reliable science of bumps or 

 bumpology. Moreover, it is known that great distortion of the brain 



FIG. 374. Artificially deformed skull 

 of ancient Peruvian, the bone showing 

 marks of the bandages used in the 

 compression. ( Types of Mankind.) 



by artificial means does not es- 

 sentially affect the development 

 of the intellectual and social 

 faculties. The ancient Mexi- 

 cans and Peruvians were addict- 

 FIG. 374. e( ^ to this remarkable fashion, 



but it did not reduce the average bulk of their brain below that of the 

 other American tribes ; viz. , 76 to 79 cubic inches, and they must be 

 regarded as at least equal in intellectual and social development. 



