MEMOIRS OF THE NATIONAL ACADEMY OF SCIENCES. 



201 



We have selected a series of 42 skulls of the so-called Mound- Builders of the Mississippi Valley. 

 These have been collected for the most part in Illinois. Kentucky, Tennessee, and Wisconsin. 

 Whether or not they represent a homogenous race has not been accurately determined; but it 

 appears to be pretty well established t hat they lived largely upon the products of the soil of which 

 inai/.e formed (lie chief staple. It is also probable that they subsisted to a certain extent upon lish 

 and game, but it is believed that they were tillers of the soil rather than hunters. An examina 

 tion of this series reveals 16, or .about , 5S per cent, in which caries is present. Of the remaining 2(5, 

 in 4 cases there was atite-mortein loss with obliteration of the alveoli which, if due to decay, would 

 increase the percentage to about 47. 



Passing now to the California, Coast Indians we find a people whose diet probably consisted 

 largely of fish, although it is well known that berries, grass seeds, acorns, and various vegetable 

 substances formed a part of their food. In this series of 38 skulls 5, or over 13 per cent, exhibit 

 dental caries. 



Of the dwellers of the open plains we include, .&quot;&amp;gt;t skulls of the Sioux. As is well known these 

 people have lived for many generations upon an almost purely animal diet. The Buffalo, until re 

 cently furnished their chief staple of food, very little vegetable substance being consumed. Among 

 this number but &quot;&amp;gt;, nearly 9 per cent, out of . 54, show any caries. These skulls were gathered over 

 twenty years ago while game was still abundant in the Sioux country. Those with carious teeth 

 are all from eastern bands who had, even then, begun to use the food of white people to some 

 extent. 



Lastly we come to the Alaskan Indians, who were probably the most exclusively carnivorous 

 people in existence except the Kskimo. Out of 42 skulls examined we, have failed to find a 

 single case of caries, although abscess and premature loss of teeth are present in S cases. 

 We are inclined to believe that abscess and premature loss of teeth is more due to accident 

 and violence than decay. It has often been noted of these people that the teeth are extensively 

 used as a sort of vise for many operations, and it would not be at all surprising if they sustained 

 occasional injuries leading to the formation of abscess and not infrequent loss. 



With this evidence before us it can not said that a meat diet is injurious to the teeth or a 

 vegetable diet especially beneficial. 



TABLE P. Dental caries among different American peoples. 



Deformity. The malposition of the teeth or deformity of the dental arch is of very frequent 

 o-curreuce in the skulls of the Salado Valley people. Out of . !(&amp;gt; skulls it is found to a greater or 

 less extent in KJ, making over .&quot;&amp;gt;. ! per cent. If we divide them up into incisor, cuspid, bicuspid, 

 and molar deformities we find that there are nine cases of malposition of the incisors, six in 

 which the cuspids are affected, live of the bicuspids, and three of (he molars. There is one 

 interesting case in which the canine of the left side had been displaced outward by the persist 

 ence of a milk tooth occupying a position between the lateral incisor and the first bicuspid. 



There are many of these cases of deformity associated with caries of the teeth, more especially 

 in those situations favorable to the lodgment of particles of food. Deformity appears to have 

 been a fruitful cause of decay. 



Among the Peruvians, out of (&amp;gt;~t skulls we are able to find only 7, or nearly 11 per cent, in 

 which there was any deformity of the denial arch. In these skulls the arch is well rounded and 

 the teeth are very regular, resembling in this respect the form of arch displayed by the Alaskans. 



