CHAPTER VI 



THE BONES— SINUSES OF THE SKULL 

 THE BONES— FRACTURES 



It is unnecessary here to give a full description of the osteology of 

 the skull, and for our purposes it will suffice to describe those parts 

 which are the seats of the more common fractures. 



In our superficial examination, the large subcutaneous area of bone 

 extending from the divergent ridges formed by the splitting up of the 

 sagittal crest above, to the nasal peak below, was described. The bones, 

 which are here subcutaneous, namely, the frontal, nasal, and parts of the 

 superior maxillary, malar and lachrymal bones, for the most part form the 

 anterior boundaries of the frontal and maxillary sinuses, and the nasal 

 fosss. 



Although these bones are of a very firm consistency, being made up 

 mostly of compact tissue, their plate-like form and their position relative 

 to the underlying cavities, render them very liable to fracture, as a result 

 of blows and injuries received over the area named. Such fractures are 

 very common in colliery ponies, owing to the head coming into contact 

 with spars of timber, etc., which project from defective roofs into the 

 colliery passages. In these cases the fractures usually occur in the 

 inferior half of the area named, since the concussion of blows received 

 over the region of the frontal bone is limited by the pad which these 

 ponies usually wear suspended from the poll-strap of the bridle as a 

 protection against " roofing " of the poll. The fractures frequently 



