PLATE 2 



EXPLANATION OF FIGURES 



5 Rabbit, age forty-six days. A portion from the center of a nodule of 

 Payer's patch, showing the abundance of acidophilic macrophages (degenerating 

 lymphoid hemoblasts), some with nuclear remnants of small lymphocytes as 

 inclusions. Other degenerating small lymphocytes are also found. Photo 

 X 750. 



6 Rabbit, adult. To show the appearance of a nodule of Peyer's patch, 

 following injection of a 5 per cent trypan blue solution into the intestinal wall. 

 The acidoi)hilic macrophages which are found chiefly in the central portion have 

 lihagocytized large quantities of the dye. Photo X 180. 



7 Rabbit, age twenty-eight days. Showing very extensive erythropoietic 

 foci in the sub- and internodular connective tissue in the region of Peyer's patch 

 These foci appear as dark masses of cells. Photo X ISO. 



206 



