5 
Ta 
1886.] On Lemurine Reversion in Human Dentition. 943 
contained in the following five collections: those of the Academy 
of Natural Sciences of Philadelphia; of the Army Medical Mu- 
seum of Washington; of the College of Physicians of Phila- 
delphia ; of the University of Pennsylvania, and of my own mu- 
seum. The first of these is especially valuable on account of the 
negro, Egyptian and Hindoo crania it contains. My acknowledg- 
ments are due to the Board of Curators, of which Professor Leidy 
is chairman, for the opportunity of studying it. The collection of 
the Army Medical Museum at Washington is especially import- 
ant on account of the Kanakas, Esquimaux, Peruvians and North 
American Indians which it possesses. I am under great obliga- 
tions to its distinguished director, Dr. J. S. Billings, for the facili- 
ties which he placed at my disposal. The museum of the Phila- 
delphia College of Physicians contains the collection made by the 
late Professor Hyrtle, of Vienna, of crania of Eastern and Medi- 
terranean Europeans. In this department it is unrivaled, and I 
am greatly indebted to the council of the college, and its curator 
Dr. Guy Hinsdale, for the opportunity of examining it. Some 
French skulls in the University of Pennsylvania were of value in 
the investigation. My own collection, though small, contains a 
number of Maoris, Australians, Tahitians and North American 
Indians, which have proved to be of importance. Of English 
and Anglo-American crania I have been able to examine but few 
of what might be termed the thoroughly amalgamated race. Of 
the latter there are probably many crania in the war collection of 
the Army Medical Museum, but how free the race of each may 
be from foreign intermixture, of course, it is impossible to know. 
In Selecting such as are supposed to be “stock Americans,” those 
of persons with ‘English names have been preferred, although 
Many now true Americans are of German ancestry. In order to 
Increase the list of this class of examinations, I have imposed on 
the forbearance of my friends by frequent inspections of their 
dentitions in ore aperto. ; 
I suspect that the characters thus obtained will prove of im- 
Portance in a zodlogical and ethnological sense. They have been 
ready found to be of great fixity, and hence significance, in the 
wer Mammalia. The only reason why they should be less so 
* 
MM man is that the modification in reverting to the tritubereular — 
molar is a process of degeneracy, and may be hence supposed to 
less regular in its action than was the opposite process of 
