some dental Rudiments in human crania. 295 



these rudiments though this is a point which should be worked 

 out in detail; but just now there seems to be do direct inference 

 to be drawn from this subject in respect of the exact nature of 

 the rudiments. 



In looking at the second question, the factors influencing the 

 frequency of occurrence, it at once appears that while Sex has 

 no appreciable effect and Age but little, that of Race is most 

 unmistakable. To begin with, we found no instances in three 

 hundred crania of Egyptians and only one in about fifty crania 

 of Europeans examined : whereas in the negro races and aborigines 

 of Australia the frequency is, comparatively speaking, very great. 

 Of all these, however, the natives of New Britain seem to present 

 by far the greatest number, both absolutely and relatively, of 

 cases of the abnormality. The aborigines of New Britain are 

 followed by those of Australia and these by African negroes: the 

 American races also appear; but whereas the number of Peruvians 

 examined was considerably over 100, only two presented signs of 

 these rudiments. These facts claim attention for this subject, 

 whatever be the exact nature ascribed to the abnormalities. 



Finally, on examining a large series of crania of Anthropoid 

 Apes, the answer to the third question indicated is, that here also 

 occurs a curious variation in the mode of occurrence : for none 

 of the lower primates (about twelve were examined) afforded a 

 case ; no occurrence was seen in six crania of Hylobates, and four 

 of Chimpanzees : among the Orang-utans available was one very 

 important specimen which alone (out of nine skulls) shewed the 

 occurrence, whereas no less than seven out of thirteen Gorilla 

 skulls presented examples of various modifications of the anomaly. 



The Orang-utan skull deserves a word of special mention : 

 the rudiments occurred in the mandible, not only between the 

 2nd premolar and 1st molar, but also between the 1st and 2nd 

 molars on the left side : now in the latter case there could be 

 no question of the retention of a temporary tooth or a fragment 

 of the same, for the temporary series does not extend backwards 

 beyond the position of the second premolar. This we regard as 

 evidence of the independent origin of the fragment but we 

 recognise that it is difficult to argue from the case of an Orang- 

 utan to that of Man. 



The extraordinary frequency of the occurrence of these 

 anomalies in Gorilla skulls certainly points in the same direction 

 as the evidence from the Orang mandible. We would therefore 

 conclude by expressing the belief that though a classification of 

 these rudiments may be needed, yet some of them really repre- 

 sent aborted teeth which, if fully developed, would confer on Man 

 a dentition formula identical with that of the platyrrhine apes. 



In expressing this belief we admit that we are aware that there 



