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Mr. Callender on the Bones of the Face. [June 18, 



fectly acquainted, such as the growth of the maxilla, and the formation 

 and subsequent obliteration of the intermaxillary bones. As they are 

 simply a narration of facts, it is almost impossible to give a satisfactory 

 abstract of them. 



After brief consideration of the arrangement of the cartilages for the 

 ethmoid and turbinate bones and for the septum of the nose, an account 

 is given of the appearances observed in a human foetus four-tenths of an 

 inch long, noticing the relations of the maxillary lobes, of the parts which 

 represent the palate, and showing that the opposite sides unite from before 

 backwards to form the palate, the soft palate remaining ununited in a 

 foetus one inch and five-tenths long. The superior maxilla is described, 

 before ossification has commenced, in a foetus nine-tenths of an inch long. 

 Although ossification begins in this bone at many distinct points, the ra- 

 pidity with which the separate ossifications are fused make it undesirable 

 to name each as a distinct centre. The palatal and alveolar portions are 

 formed somewhat later than the rem.ainder of the bone. In a foetus two 

 inches and three-tenths long the bone consists of a nasal process, deeply 

 grooved on its inner surface, of an incisor process, which has not hitherto 

 been accurately described, of orbital and of palatal- alveolar portions ; the 

 infraorbital fissure is distinctly marked, and a deep notch shows the situ- 

 ation of the canine socket. 



The principal changes which are noticed during the growth of the bone 

 result from the thickening and marking of the nasal process, the forma- 

 tion of the nasal groove and of the inner and outer walls of the antrum, 

 the variations in the relative size of that cavity, the deepening of the sockets 

 for the teeth, the formation of the septa dividing them, and the changes in 

 the orbital plate. The order and method of these changes are separately 

 narrated. 



The ossification of the vomer is shown to commence from its inferior 

 and anterior parts, whence also ossification extends to the intermaxillary 

 bones, which are formed in the membrane bounding the anterior nares. 

 Each of these bones acquires its greatest independent size in a foetus about 

 four inches and a half long, and then consists of a nasal process, which 

 eventually fuses with the corresponding portion of the superior maxilla, its 

 apex assisting to form the ridge for the turbinate bone, and of plates which 

 strengthen the incisor portion, and form part of the walls of the incisor 

 sockets. In a foetus six inches and seven-tenths long the apex alone is 

 distinct, and in a foetus nine inches long the bone is lost in the upper 

 maxilla, although the fissure along its posterior margin still outlines its 

 shape. The bone grows in the fissure between the incisor process and the 

 palate, and is shut off from the face by the first-named and by the nasal 

 process. Distinctly outlined at the close of the fourth month, it is joined 

 to the superior maxilla during the latter part of the fifth or beginning of 

 the sixth month. 



Some facts are related respecting the formation of several of the remaining 



