TENDONS. 153 



tiguous surfaces of bones come together, by rather a smooth 

 surface and without any serration, as in the nasal, superior 

 maxillary, and palate bones. Schindylesis (40*8*4** a fis- 

 sure,) is also a variety of suture, and consists of a fissure or 

 gutter, by which one bone is received into another, as the 

 vomer, the sphenoid, and ethmoid. Gomphosis (70^05, a 

 nail,) is that species of articulation where the bone is fitted 

 to another, after the manner of a nail that is driven in a 

 board. The teeth are specimens of this variety. Am- 

 phiarthrosis, (a^c, both, a P 9ov, articulation,) as its name 

 implies, partakes of the character of both the diarthrosis 

 and synarthrosis; that is, it has a little of the motion of 

 the former, and, like 'the latter, is without synovial mem- 

 brane, as in the bones of the vertebrae. 



The union of the scapula, or shoulder-blade, to the trunk, 

 by means of muscle, called syssarcosis, (<nw, together, <yopi, 

 flesh,) and symphysis, as in the symphysis pubis, sacro-iliac 

 symphysis, &c., are also considered as belonging to this 

 form of articulation. The motions of joints are reduced 

 to four varieties the angular motion, circumduction, rota- 

 tion, and gliding. Angular motion comprises flexion, ex- 

 tension, adduction, and abduction. Circumduction is the 

 small amount of motion which the head of the . humerus 

 and femur make with their articular cavities, when their 

 extremities move in a large circle. Eolation is the mo- 

 tion which a bone describes upon its own axis, as illus- 

 trated in the movements of the radius upon the humerus, 

 or the atlas upon the dentata. The gliding motion is found 

 in the carpus and tarsus, and, in some degree, in all the 

 joints, and is the simple movement of one articular surface 

 upon another. 



TENDONS. 



The tendons have been already noticed under the head 

 of the muscular tissue, and we will here only speak of the 

 points in which they differ from ligaments. They differ 

 in color ligaments rather inclining to yellow, while ten- 

 dons are pearly white. They differ in function ligaments 



