16 * THE TONER LECTURES. 



separate. The association of bones above named will receive in 

 this connection the name of the anterior cranial segment. 



The squamosal portion of the temporal bone unites with the 

 malar bone, while the element first named is in articular union 

 with the lower jaw, thus a natural series on the side and the base 

 of the skull is constituted. The most intimate relations of this series 

 are with the bones of the anterior segment rather than with the 

 parietal, and it may receive the name of the squamoso -malar series. 



The petrosal elements early unite with the squamosal, but never 

 exhibit inclinations to unite with the occipital or sphenoid bones. 



The occipital and parietal elements are also distinct, and nothing 

 can be claimed to show their disposition to unite in any definite 

 manner to one another or to any of the groups above named of 

 cranial bones. 



In reviewing the above facts it is seen that the sphenoid and 

 frontal bones have facial affiuities ; that the squamosal and malar 

 bones form a natural series, which tend to embrace the .lower jaw, 

 but that nothing in the attempt to demonstrate affinities by their 

 predilections in articulation can be shown for the parietal or occip- 

 ital bones. 



Conceding that variations in bones are to be studied in connection 

 with the changes in the groups to which they belong, it follows that 

 the variations of the face should iuclude those of the sphenoid and 

 frontal bones ; that the squamosal, malar, and inferior maxilla 

 should be studied together, and that the remaining bones cannot be 

 studied as a whole. 



The anterior segment can be easily separated from the parts lying 

 back of it by the line of the occipito-sphenoid junction. When 

 the junction is obliterated a hypothetical transverse line^ joining 



^ The transverse line answers necessarily to the place of the former su- 

 ture which unites the sphenoid and occipital bones. Some writers assert 

 that the transverse depression seen in the adult skull is not sutural, but 

 muscular. This is not the case. The two lines are distinct. They are 

 clearly seen as such in No. 87 Carniola (College of Physicians) and ob- 

 scurely so in many specimens. 



