34 



CONNECTIVE TISSUES 





The culmination of these changes results in the mature fibrillar 

 connective tissue in which the cells are shrunken and scarce, 

 though still apparently capable of assuming renewed activity when 

 occasion requires. 



Embryonic connective tissue is therefore typically cellular as 

 compared with the mature type ; its ground substance is abundant, 

 but the fibres, whose development is as yet incomplete, are scanty. 

 Such embryonic connective tissue is found not only in the fetus, 

 but also in early childhood, and in the adult especially during re- 

 generation of destroyed areas of connective tissue, and in other 

 more or less pathological conditions. 



Connective Tissue Cells. Connective tissue cells not only vary 

 in number as they -approach maturity, but in their structure and 

 appearance as well. The cells of embryonic connective tissue are 

 comparatively large, are frequently stellate 

 r^ from the presence of numerous interlacing 



and sometimes anastomosing branches, and 

 their cytoplasm has a typical reticular or 

 granular appearance. In the later stages of 

 their development ameboid motion has been 

 observed in such cells, and, within the limits 

 of the tissue in which they are developed, 

 they are presumably endowed with the power 

 of locomotion. 



In the neighborhood of developing blood- 

 vessels plasma cells of large size and irregular shape are frequently 

 seen. The cytoplasm of these cells is of considerable volume, 

 and is prolonged into broad protoplasmic 

 branches of considerable length. Both 

 in the cell body and in the processes 

 vacuoles are so numerous as to give the 

 cell a typically reticular appearance, a 

 peculiarity which is emphasized by the 

 removal of the contents of the vacuoles, 

 as frequently happens in the preparation 

 of microscopical specimens. 



In the denser forms of mature connective tissue, where the 

 cells are apparently subjected to more or less compression between 

 the firm bundles of fibres, the connective tissue cells lose their 

 typical embryonal stellate form and become somewhat fusiform ; 

 they are then known as the spindle cells of connective tissue. Such 



FIG. 35. PLASMA CELLS 

 OF CONNECTIVE TIS- 

 SUE FROM THE HU- 

 MAN BREAST. 

 Hematein and eosin. 

 x 750. 



FIG. 36. SPINDLE-SHAPED CON- 

 NECTIVE TISSUE CELLS FROM 

 THE STROM A OF THE HUMAN 

 OVARY. 



Hematein and eosin. x 550. 



