THE CONNECTIVE TISSUES. 



81 



latter which either form a wide-meshed reticulum, interlacing with 

 the bundles of white fibres, or are applied to the latter in a sort of 

 open spiral, binding them together. In the developing tissue the 

 cement- or ground-snbstance at first fills all the interspaces between 

 the cells and the fibres ; but as development proceeds spaces appear 

 in the tissue, which are occupied by lymph and intercommunicate 

 throughout the tissue. The ground-substance is then restricted to 

 a mere cement uniting the fibres within the bundles and laminae. 

 The flat or endothelial cells of the tissue lie within these bundles or 

 are applied to their surfaces, forming a more or less perfect lining 

 to the lymph-spaces within the tissue and becoming continuous with 

 the endothelial walls of the lymphatic vessels. It is within these 

 spaces that the lymph accumulates after its passage through the 

 walls of the smaller bloodvessels, to find its way into the lymphatic 

 circulation. The spindle-shaped and cuboidal cells of the tissue lie 

 between or within the bundles of fibres embedded in the cement- 

 substance (Figs. 65 and G6). 



Fig. 65. 



Areolar tissue. Preparation from the subcutaneous tissue of a young rabbit. (Schafer.) 

 c\ endothelioid cell; p,p, cells with granular cytoplasm ; c, c, /, cells of the fusiform or 

 stellate variety not yet fully developed. The white fibres are in bundles pursuing a wavy 

 course; the elastic fibres are delicate and forma very open network; g, leucocyte of a 

 coarsely granular variety. 



Areolar tissue varies greatly in different situations in the density 

 of its structure — i.e., in the size of the fibrous bundles and their 

 relative abundance, as compared with the number and size of the 



6 



