74 THE HUMAN BODY. 



tition between the dorsal and ventral cavities which in the 

 trunk is made up of the bodies of the vertebrae. In very 

 early life it presents in the middle line a series of four 

 bones, the basi-occipital, basi- sphenoid, presphenoid, and 



Tsp 



Fio. 26. A side view of the skull. O, occipital bone; T, temporal; Pr, parie- 

 tal; F, frontal; S, sphenoid; Z, malar; MX, maxilla; N, nasal; .E, ethmoid; L y 

 lachrymal; Md, inferior maxilla. 



basi-ethmoid, which answer pretty much to the bodies of 

 four vertebrae, and have attached to them the thin bones 

 which inclose the skull cavity (which may be likened to 

 an enlarged neural canal) on the sides and top. In the 



