COMPARATIVE ANATOMY OF THE TEETH. 275 



ifest and characteristic of the orang, and the outer angle of 

 the lateral incisors is more rounded off in this quadruman. 

 The crown of the canine is longer and more pointed in the 

 chimpanzee than in man; still more so, and farther apart 

 from the incisor, in the orang. The first molar is as large 

 in the human subject as in the chimpanzee, and its crown is 

 divided into two principal cusps, hut the outer and larger 

 one has a small subdivision notched off posteriorly, and the 

 inner cusp is relatively larger than in the chimpanzee. The 

 first upper molar of the orang is simply bicuspid, but is 

 larger than in the chimpanzee. The second molar of the 

 human child could scarcely be distinguished from that of 

 the young chimpanzee, both are quadricuspid, and the same 

 oblique ridge crosses the grinding surface from the ante- 

 ro-internal, to the postero-external tubercle, but the pointed 

 summits of the two outer cusps are a little more extended 

 in the chimpanzee. The second molar of the orang, besides 

 its larger size, has the four tubercles better defined, and the 

 oblique ridge less developed. 



" The lower deciduous incisors of the anthropoid apes 

 differ from those of the human subject in their superior 

 size, greater relative thickness, and the lateral incisor more 

 particularly, by the rounding off of the auter angle. 



"The lower canine of the chimpanzee has a larger, 

 longer, and more pointed crown, with a sharp posterior 

 edge; this is less marked in the canine of the orang, which 

 is larger arid thicker than in the chimpanzee; the crowns 

 of the upper and lower canines are more obliquely opposed, 

 the lower one being more advanced in those apes than in the 

 human subject. 



" The first lower deciduous molar of the human subject 

 has four tubercles and a small anterior ridge, and is larger 

 than that of the chimpanzee, which supports a single large 

 pointed cusp and a posterior ridge. The first molar of the 

 orang has a similar simple crown, but is as large as that 

 of the child. The second molar is of equal or superior size 

 in the human subject to that in the chimpanzee, but it 

 supports three outer and two inner cusps, while in the 



