CONNECTIVE TISSUE. 



241 



formed cartilage, is of a later date ; f. i., in the vertebra?. (See 

 Fig. 96.) 



In new-born pups, kittens, and rabbits these features are 

 very similar, though sometimes the calcification preceding the 

 ossification is wanting, even in shaft-bones (see, f. i., Fig. 98). 

 It is wanting, as a rule, at the cartilaginous border of the plate 

 of the scapula. 



FIG. 97. VERTEBRAL EXTREMITY OF THE BIB OF A HUMAN EMBRYO, TEN 

 WEEKS OLD. HORIZONTAL SECTION. CHROMIC ACID SPECIMEN. 



H, hyaline cartilage, with mostly multiple formations of corpuscles in the territories; 

 C, calcified frame of basis-substance ; P, cartilage corpuscles with jagged offshoots, enlarged 

 by liquefaction of the basis-substance. Magnified 500 diameters. 



We know that the calcification of cartilage is the first step in 

 the development of bone, and as this process takes place inde- 

 pendently in three portions of the shaft-bones, three nuclei of 

 16 



