CHAPTER III 



CONNECTIVE TISSUE CARTILAGE BONE 



CONNECTIVE TISSUE 



General Statements. While in the epithelial tissues the cells are 

 developed chiefly at the expense of the intercellular elements, in the 

 connective or supporting tissues the conditions are the reverse. The 

 intercellular elements are here developed out of all proportion to the 

 connective tissue cells. The cells of these tissues therefore are scanty, 

 the ground substance considerable, and within the latter a new element, 

 the connective tissue fiber, makes its appearance. The fibers are of three 



*' K 



FIG. 55. EMBRYONAL CONNECTIVE 

 TISSUE, EARLY STAGE. 



Highly magnified. (After Mall.) 



<= 



" '" 



I o M 



^ ? -^o *.. 



FIG. 56. EMBRYONAL CONNECTIVE TIS- 

 SUE AT A LATER STAGE THAN Is REP- 

 RESENTED IN FIG. 55. (After Mall.) 



varieties: ichite or collagenous fibers, elastic fibers, and n'lici/Jitm. In 

 any given location either of these varieties may predominate to such an 

 extent as to determine the character of the mature tissue, while in the 

 immature forms of connective tissue it is the cellular elements which 

 attain the greatest prominence. 



The minute structure of connective tissue is subject to great and 

 important changes during its development. Beginning as it does with 

 the primitive mesoderm, connective tissue is originally a cellular struc- 

 ture. The cells of primitive connective tissue, the fibrobl*t*. not only 

 increase in number by cell division but also secrete an intercellular 

 ground substance of semifluid consistence. The fibroblasts fuse with each 

 5 49 



