4.98 ARMAND RUFFER. 
phages, similar to those found in the Peyer’s patches, the 
intracellular yellowish-grey bodies being simply digested leuco- 
cytes. It would be a useless repetition to describe here again 
the formation of these cells. All that need be said is, that 
they are developed from the lymphocytes of the tonsils in the 
same way that the macrophages of the Peyer’s patches are 
developed from the small round-cells of the lymphoid tissues. 
They never attain quite the same size in the tonsils as in the 
intestines, but they appear to be more mobile as they are met 
with close to the free surface. Although present in the 
lymphoid tissues of the tonsils they are not very numerous 
there. 
The macrophages of the dog do not, as a rule, advance into 
the epithelial layer, but huge agglomerations of macrophages, 
forming nest-like masses of cells, are often found just below 
the epithelial border. These macrophages are crammed with 
dust, carbon particles, and all kinds of foreign matter (figs. 
IG, a,b 17, a, 0,.¢,a3 18, a; 19, a). They also contain 
dead leucocytes, together with the extraneous matter which 
the latter had fetched from the surface (figs. 17, e, f, g; 
18 c, d; 19,6). These agglomerations of cells are some- 
times so large that, on cutting across a dog’s tonsil after 
soaking it in paraffin, small black dots are seen with the naked 
eye, which prove to be masses of these large cells. These nests 
resemble, in all particulars, those found in the rabbit’s Peyer’s 
patches. 
If the sections be stained with Loffier’s blue or gentian-violet, 
some of the macrophages in the rabbit and dog are found to 
contain numbers of micro-organisms (see figs. 18 and 19). 
These are generally micrococci, though bacilli are also found. 
Some of these micro-organisms present normal staining re- 
actions, but others do not retain aniline dyes and show all the 
appearances of intracellular digestion which have heen described 
in the Peyer’s patches. Although unable to obtain a man’s 
fresh healthy tonsils, I have, in three healthy men and one 
woman, met with many leucocytes full of microbes on examining 
the mucus removed from the surface of these lymphoid organs. 
