CHAPTER III 

 CONNECTIVE TISSUES 



WHILE in the epithelial tissues the cells are chiefly developed 

 at the expense of the intercellular elements, in the connective 

 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 fibre, makes its appearance. The fibres are of 

 three varieties : white connective tissue fibres, yellow elastic fibres, 

 and reticulum. 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 promi- 

 nence. 



The minute structure of connective tissue is subject to great 

 and important changes during its development. Beginning, as it 



^:P 



^m^ & 

 ^.j&? -. -*.** .,-. 



i^e^p^ig- 



FIG. 32. EMBRYONIC CONNECTIVE TISSUE, FIG. 33. EMBRYONIC CONNECTIVE TISSUE AT 

 EARLY STAGE. Highly magnified. A LATER STAGE THAN is REPRESENTED 



(After Mall.) IN FlG - 32 - (After Mall.) 



does, with the primitive mesoblast, connective tissue is originally 

 a cellular structure. The mesoblastic germ cells of connective 

 tissue not only increase in number, by cell division but also secrete 

 an intercellular ground substance of semifluid consistence. The 

 32 



