84 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 83 



the roots of the teeth. No such condition was found in the chimpanzees, though 

 occasionally the limits of the enamel in their teeth are not easy to determine. 



The crown of the chimpanzee molars in the majority of cases shows, particu- 

 larly externally, a marked bulge just above the gum ,(" cingulum "), from 

 which the cusps slope more or less upwards. Externally this slope is sometimes 

 very decided. In man, and that in early as well as recent man, the bulge mostly 

 becomes just a convexity and the cusps are more vertical, making the surface 

 of the crown larger. In the Piltdown teeth conditions are exactly as in human 

 molars. 



The Piltdown molars are moderately worn down to the level of the depres- 

 sions between the cusps. These depressions as far as preserved, and the wear 

 itself, are very much as they are in man. In the chimpanzees such depressions 

 show some differences from both the prevalent human and the Piltdown type, 

 and the wear of the teeth is generally irregular. But there is a chimpanzee jaw 

 of the National Museum series (No. 84,655) in which the wear is about the same 

 as in the Piltdown and many human molars, and there are not infrequently human 

 molars in which the wear will be irregular. Nevertheless, in this feature again 

 as in other characteristics of the crown, the Piltdown teeth range themselves 

 on the whole closer to human than to the chimpanzee type. 



The crowns of the Piltdown teeth, in their height, find nothing resembling 

 them in the teeth of the chimpanzee, but are closely like those of both early and 

 modern man. This is one of the most important features in which the Piltdown 

 specimen differs from the apes. The height of the crown from the uppermost 

 part of the root notch to the level of the base of the furrows between the cusps, 

 is externally in each of the Piltdown molars 8.5 mm. This can readily be dupli- 

 cated in man; but the available chimpanzees give only (M2):5.5; 6.0; 6.5; 

 6.0; 6.5; 7.0; 6.5; 6.0; 6.0; 6.0; 6.5; 6.0 mm. The Piltdown, Mauer, Brelade 

 (Jersey) and recent human teeth (in general) are high-crowned or hypsodont ; 

 the chimpanzees are as a rule low-crowned or chamaedont. A jaw with molars 

 such as those of the Piltdown specimen cannot be that of a chimpanzee, unless 

 we should arbitrarily assume some old form of that genus that was radically 

 closer than recent chimpanzees are to the human type. 



The height of the enamel on the crown is in general difficult to measure due 

 to the irregularity of its lower limits. In the Piltdown teeth the condition is 

 further aggravated by the wear of the teeth. Notwithstanding all this, it can be 

 estimated that the enamel layer of the Piltdown molars averages externally very 

 close to 6 mm. without the cusps and that with the latter it reached 7.5 mm. 

 These dimensions are common in man, both old and recent ; but they are never it 

 seems equalled in the chimpanzees. Taking the total height of enamel on the 

 external surface of the Piltdown molars, with the cusps restored, as 7.5 mm., 

 the nearest approach in a chimpanzee (British and U. S. National Museums) 

 was 6.5 mm., and from this the measurements ranged to 5 mm., the most frequent 

 figures obtained being 5.5 and 6 mm. Here then there is again an important 

 difference. 



The size of the individual molars in the Piltdown jaw is for Mi, length along 

 middle, 13 mm., breadth max. at right angles to length, 11 mm.; M2, length 

 13 mm., breadth 11 mm. ; length-breadth index of each 84.6. The worn surface of 

 the crown of the second tooth appears to the eye a .trifle larger than that of the 

 first molar, but on measurement the teeth are found to be so closely alike that a 



