SOCIETY OF THE UNIVERSITY OF ABERDEEN. 197 



nun., whereas the measurement on the opposite side was 168 mm., 

 there thus being an increase of 20 mm. on the side presenting the 

 additional suture. 



To sum up the principal conclusions to be drawn from a con- 

 sideration of these cases of abnormal sutures, it will be seen that they 

 afford evidence :: 



1. That the growth of the cranial bones takes place principally 

 at their edges, and not to any extent by interstitial growth or deposit 

 of bone upon the surface and absorption from within. 



2. That if this growth is prevented by an early synostosis of the 

 sutures, the diminution in size of the bones in one direction is largely 

 compensated for by an increased growth in other directions, producing 

 deformities such as scaphocephaly, trigonocephaly, or plagiocephaly. 



3. That in cases in which an abnormal suture is present, such as 

 the transverse occipital, the increase in the bone in which the suture 

 is present, is partly at the expense of the adjacent bones and partly 

 adds to the total capacity of the skull. 



5. PHYLOGENETIC AND KACIAL DIFFERENCES. 



Our knowledge of certain intermediate stages in the phylogeny of 

 the human race is imperfect. Anthropology has, however, from time 

 to time received a fresh stimulus by the discovery of certain bones 

 which are believed by the most eminent scientific authorities to be 

 human, and which are of interest, not only as showing the antiquity 

 of man, but also as supplying that link which was looked for by 

 Huxley and his contemporaries between man and his supposed 

 pithecoid ancestors. 



I shall commence with a brief consideration of the principal 

 characters of the skull of " pithecanthropus erectus," which was dis- 

 covered in 1892 by Eugene Dubris. It was found in pliocene 

 strata in Java, at Trinil. The skull is of a low type, and is believed 

 to hold an intermediate position between thr- living races of mankind 

 and the higher apes. With the skull were found three teeth and the 



