EAKLY GrKOWTH OP THE BONES OF THE HUMAN FACE. 
169 
I have never seen anything like an approach to the formation of a distinct anterior 
plate of bone, such as forms part of the preemaxillse of mammals. 
Yet, despite the peculiarity which results from the formation of the incisor process 
and the shutting in of the intermaxillaries in Man, these bones closely resemble those 
corresponding with them in mammalia. They have a similar wedge-shaped articular 
surface, fitting a groove in either superior maxilla ; they extend towards the middle line 
and articulate there ; they form the anterior extremity of the palate ; they bound and 
divide the incisive foramina; they assist in forming no inconsiderable portion of the 
sockets for the incisor teeth ; that they do not completely form them is a fact occasionally 
confirmed by the imperfect character of the sockets which lodge these teeth in those cases 
of cleft palate which have the intermaxillary bones isolated from the superior maxillae. 
Another interesting point may be noticed. In some mammals having a slight upper 
jaw, a Sheep for example, the outer wall of the nostril is smooth, there is no vertical 
ridge, such as that which in Man rises to the turbinate bone. In other mammals with 
strong upper jaws the praemaxillae thicken towards their articulation with the superior 
maxillae, and here is the most prominent vertical line on the nasal surface ; beyond this the 
superior maxillae recede somewhat. There is no such distinct ridge on the upper jaw 
itself. In Man the corresponding ridge is placed about the middle of the inner surface 
of the ascending process of the upper maxilla, but it results from, and marks none the 
less the junction of the nasal process of the intermaxilla with that groove on the inner 
surface of the upper jaw with which it originally articulated. 
A few words may dispose of several of the bones of the face, as there is little that is 
new to be said respecting them. In a foetus 1*5 ossification has commenced in the nasal 
bones; in a foetus 2'3, and still better in one 3 - 7, the outer lower angle is seen to be 
prolonged downwards, and is in connexion with the fold of membrane continued up 
from the apex of the intermaxilla. The lachrymal bones are incompletely ossified in a 
foetus 2-3 They are formed in membrane, covering a prolongation of cartilage from that 
which eventually forms the ethmoidal plate of the orbit. One of these bones is seen in 
position in a specimen from a foetus 4*7. The ossification of the malar and of the palate- 
bones progresses with that of the upper jaw. That of the palate-bones takes place in 
the inner and back part of the maxillary lobe. In a foetus 1*5 the palatal portion is 
represented by a slightly incurved ridge, the vertical is proportionately much larger. 
The bones are in the earliest stage remarkable for the large size of the posterior nasal 
foramen, around which ossification appears to commence. The remarkable size of the 
opening for the malar nerve and the early bone-deposits around it, the formation of the 
nasal bones over branches from the ophthalmic nerves, the building-up of the superior 
maxilla about the infraorbital and its branches, and of the inferior maxilla about the 
dental nerve, are points worth noticing with reference to the formation of these bones 
of the face. In a foetus 9 inches long the palate-bone is completely outlined, with the 
exception of the surfaces which mark its upper processes. 
