THE MAST CELLS 



put forward in the Ehrlich Centenary Lecture on the Mast Cells (Riley, 1954) 

 by directly relating the release of metachromatic material from the mast cells 

 to the fresh formation of ground substance by the connective tissue cells. 



embryo 



adult 



chronic [protein-rich] chronic lymphatic 

 oedema obstruction 



4++ 



healed scar 

 O 



Fig. 53 



Diagram to show the participation of the mast cells in the dynamics of 



the connective tissues. Mast-cell content is indicated by the signs O to 



+ + + ; the cross-hatching indicates metachromatic ground substance. 



(See Riley (1954). Lancet, p. 841.) 



The proposed scheme for the participation of the mast cell in the dynamics 

 of the connective tissues, mentioned above, is illustrated in the sequence of 

 events shown diagrammatically in Figures 53 and 54. Mast cells are not present 

 in the early embryo; they appear in their characteristic locations only towards 

 the end of embryonic life when they rapidly fill with granules (Laguesse, 1919; 

 Hjelmman, 1954; Kitanishi, 1956). This is the sequence epitomized in the 



140 





