. Cunningham's Text-book of anatomy. Anatomy. 158 OSTEOLOGY. a carrot-like mass, at the condyle : the large end forms the condyle; the tapering end is wedded into the ossifying ramus under the root of the coronoid process. This cartilage appears about the eleventh week. About the thirteenth week a strip of cartilage appears along the anterior border of the coronoid process. Along the anterior end of the alveolar walls close to the middle line, and turning down the symphysial surface of the mandible to end below in the region of the future digastric impression, another mass of cartilage appears
. Cunningham's Text-book of anatomy. Anatomy. 158 OSTEOLOGY. a carrot-like mass, at the condyle : the large end forms the condyle; the tapering end is wedded into the ossifying ramus under the root of the coronoid process. This cartilage appears about the eleventh week. About the thirteenth week a strip of cartilage appears along the anterior border of the coronoid process. Along the anterior end of the alveolar walls close to the middle line, and turning down the symphysial surface of the mandible to end below in the region of the future digastric impression, another mass of cartilage appears about the fourteenth week. All the above cartilages are ossified by invasion from the surrounding membrane bone and are not therefore independent centres. It is possible that the "symphysial cartilages may be occasionally independently ossified and thus give rise to the ossa mentalia when they exist. From what has been stated it thus appears that under normal conditions each half of the mandible ossifies from one centre only. The above account is based on the researches of Low l and In a third or fourth month foetus the cartilage can be traced from the under surface of the fore part of the tympanic ring downwards and forwards to reach the jaw, to which it is attached at the opening of the mandibular canal; from this it may be traced forwards as a narrow strip applied to the medial surface of the mandible, which it sensibly grooves. The proximal end of this furrow remains permanently as the mylo-hyoid groove. The part of the cartilage between the tympanic ring and the jaw disappears, and its sheath becomes converted into fibrous tissue, and persists in the adult as the so-called internal lateral (spheno-mandibular) ligament of the temporo-maxillary articulation, its proximal end through the Gaserian fissm-e being continuous with the slender process of the malleus, with the development of which bone it is intimately associated. I. Chaine (Comptes Rendus, Biologie,
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