t'.-J PROCEEDINGS OF THE ANATOMICAL AND ANTHROPOLOGICAL 



Testut follows the description of lower jaw development given by 

 these authors. 



( 'allender (4), in 1869, published a good account of the develop- 

 ment of lower jaw in man. He shows that the bone is partly 

 developed from Meckel's cartilage, partly from the membrane which 

 covers it. He describes four centres of ossification, viz., a condyloid 

 appearing in cartilage ; a centre in membrane on the outside of 

 Meckel's cartilage; an ossification of the anterior extremity of 

 Meckel's cartilage, forming a triangular piece below the incisor teeth, 

 ;m<l remaining separate up to the fourth month of foetal life ; finally 

 deposits of bone in the perichondrium of the cartilage, giving rise to 

 the plate of bone which completes the dental canal. 



StrelzofF (20), in 1873, in a research on the histogenesis of bone, 

 states that Meckel's cartilage does not ossify or take part in lower 

 jaw formation. 



W. K. Parker (14), in 1874, in a paper on the development of 

 the skull in the pig, figures the angle and the condyle as one piece of 

 cartilage, and the rest of the mandible as membrane bone. 



Brock (3), in 1876, says that the lower jaw of the pig is laid 

 down as a slender periosteal lamella, in which no separate parts are 

 to be seen. Later, a cartilaginous nucleus appears in the position of 

 the angle, and this extends to form the hinder border of the ramus and 

 the condyle. He denies that any trace of Meckel's cartilage enters 

 into the formation of the lower jaw. 



Bauiniiller (2), in 1879, gives an account of the development of 

 the lower jaw and the fate of Meckel's cartilage in the pig. He says 

 that the anterior part of Meckel's cartilage undergoes ossification. 

 The main part of the body of the jaw, he shows, is developed as 

 membrane bone. 



Mr. J. Bland-Sutton (21), in 1883, in a paper on the development 

 of the inferior maxilla, describes six centres of ossification (Fig. 3). 

 His ((inclusions are based on macroscopic preparations of developing 

 lower jaw, and on the comparative anatomy of the jaw. He says 



