256 SKULL AND BRAIN IN MAN. 



LECTURE VI. 



SKULL AND BRAIN IN MAN. 



1. In bringing under your consideration to-day the relative 

 structural arrangements of the skull and brain in man and 

 the animal, I shall not touch on any of those topics which 

 have recently conferred on the subject a kind of notoriety, at 

 all times adverse to the progress of science, but shall confine 

 myself to points which will supply us with data for the illus- 

 tration of the special object of this course. 



The Skull. 



a. The cephalic axis (axis of head) is a right line extend- 

 ing in the mesial plane, from the anterior margin of the 

 occipital foramen, along the floor of the nose to the incisive 

 openings, and prolonged to the cartilaginous extremity of the 

 nose. The floor of the nasal fossoe in man and mammals, 

 until we come low down in the series, is remarkably straight 

 as far as the incisive foramen, at which there is a ridge. The 

 line of the cephalic axis must be taken as a central line, be- 

 cause in the examination of the axis of the spine we found 

 that its axial line came in contact through the axis vertebra 

 with the anterior margin of the foramen magnum. The 

 assumption of a line which shall represent the axis of the 

 cranium involves the idea of its being continuous with that 

 of the spine. The axial line of the head is horizontal. In 

 man alone does this line touch the posterior as well as the 

 anterior margin of the foramen magnum. 



