Warren Harmon Lewis 171 



length than in the preceding stage. The two ends are enlarged. The 

 main portion is of cartilage snrronnded by a thick perichondrihm which 

 is continuous with that of the head of the scapnla, forming the Ijegin- 

 ning of the capsular ligament. There is also a strip of perichondrium 

 between scapula and humerus in which there are no signs of a joint 

 cavity. At the proximal end the perichondrium shows thickenings for 

 the tuberosities, while at the distal end the condyles are for the most 

 part of cartilage continuous with that of the main portion. Consid- 

 erable masses of condensed tissue, however, help to increase the size of 

 the condyles. A portion of the head of the humerus rests against the 

 base of the eoracoid process, indicating that a portion of this is to be 

 incorporated with the head of the scapula. 



The ulna and radius are of cartilage surrounded by a thick peri- 

 chondrium. This is continuous with that of the distal end of the 

 humerus, forming the beginning of the capsule. The perichondrium 

 of the proximal end of the radius is continuous with that of tlie adjoin- 

 ing surface of the ulna. The cartilages of the humerus, radius and 

 ulna are separated from each other by condensed tissue in which no 

 signs of cavities are present. The olecranon is quite well developed and 

 consists mostly of cartilage. The coronoid process is mostly of con- 

 densed tissue. The great sigmoid fossa is rather shallow. The bicipital 

 tuberosity is of condensed tissue. The distal ends of these bones are 

 enlarged and separated from each other by condensed tissue continuous 

 with the perichondrium of each. 



The carpus consists of a condensed tissue matrix in which lie im- 

 bedded the various cartilages. The distal row is complete, the trapezium, 

 trapezoid, os magnum and unciform. The latter has spread in between 

 the fifth metacarpal and the cuneiform (pyramidal). In the proximal 

 row the cuneiform and scaphoid are of cartilage and the hmar and 

 pisiform of condensed tissue. 



The metacarpus shows five slender cartilages surrounded by very thick 

 condensed tissue layer or perichondrium. The first metacarpal cartilage 

 is only about one-half the length of the others. 



The ulnar four plialanges of the first row are present as short slender 

 cartilages deeply imbedded in condensed tissue. In the first digit con- 

 densed tissue takes the place of the cartilage. At the tip of each digit 

 is a mass of condensed tissue. 



There are no joint cavities between the cartilages of the hand, each 

 one is separated from its neighbor by an area of condensed tissue. 



