THE MAST CELLS 













t 





8 



** 



\ 





V;',? i 









•v 



* » »t « 



•«l 



Fig. 65 



Similar section to that shown in Fig. 64, taken from a rat fed for two months on a 

 diet deficient in calcium and vitamin-D. There is now evidence of rickets, osteo- 

 porosis and osteitis fibrosa, together with a dramatic increase in the mast-cell 

 content of the region. There is a corresponding increase in histamine and 5-hydroxy- 



tryptamine. 



158 



