398 GENERAL ANATOMY. 



bones with the vomer, the lachrymal bone with the nasal pro- 

 cess of the maxillar bone, &c. 



Lastly, Gomphosis is a species of synarthrodial articulation, 

 entirely different from the suture, which results from the re- 

 ception of the roots of the teeth into the alveoli. 



626. Jlmphiarthrosis,* or mixed articulation, partakes of 

 the nature of synarthrosis in having the articular surfaces 

 united by means of an intermediate substance, and of that of 

 diarthrosis in having a considerable degree of mobility. This 

 kind of articulation is confined to the body of the vertebrae, 

 the pubis and the upper parts of the sternum. 



The articular parts of the bones, are here flat and broad sur- 

 faces. The means of union are intermediate cartilaginiform 

 ligaments, adhering very firmly to the two surfaces, and acces- 

 sary ligaments placed at the exterior of the articulation. This 

 kind of articulation, which is often called symphysis, pos- 

 sesses a great degree of solidity, which is owing to the tenacity 

 of the ligament. Its mobility is owing to the flexibility and 

 elasticity of the same substance. The motion consists of the 

 flexion or torsion of the ligament. This articulation, which is 

 very loose and mobile in childhood, becomes more and more 

 firm in old age, at which period it sometimes ossifies. Some- 

 times the ossification is external to it, and only surrounds it 

 more or less completely, as is especially observed at the fore 

 part of the body of the vertebrae. It may be accidentally too 

 loose or too close. It is not susceptible of a true luxation, but 

 rather of a displacement, a drawing asunder, which 'always 

 supposes the laceration or destruction of the intervening carti- 

 laginous ligament. 



After certain unconsolidated fractures, there are sometimes 

 produced articulations of this kind; that is to say, the frag- 

 ments are united by the intervention of a flexible and tena- 

 cious substance, which permits them to move upon each other. 

 This mode of accidental articulations occurs after fractures of 

 the patella, the neck of the femur, the olecranon, and also 

 sometimes after those of the body of the long bones. Amphi- 



* A. Beclard. Dictionnaire de Medicine, vol. ii. 



