ON THE PHAGOCYTES OF THE ALIMENTARY CANAL. 487 
carmine and gentian-violet, or by some other method (fuchsine, 
Loffler’s blue). 
If the free epithelial border of a rabbit’s Peyer’s patch be 
examined with a high power (Zeiss, oc. 3, obj. imm. 4) it 
is noticed to have been invaded in many places by numerous 
leucocytes. I shall call these leucocytes microphages, on 
account of the power they. undoubtedly possess of taking 
micro-organisms into their interior, and of destroying them. 
Stéhr! had noticed that these microphages (leucocytes) come 
up to the free surface throughout the whole length of the 
alimentary canal. They are, however, present in greater 
numbers between the epithelial cells covering the Peyer’s 
patches than in other parts of the intestine. This is easily 
demonstrated by causing the section to pass through the 
lymphoid tissues and at the same time through the part of the 
intestine surrounding the patch; the microphages being more 
than twice as numerous between the epithelial cells covering 
the lymphoid tissues than between those placed over the 
neighbouring parts of the gut. 
The microphages are sometimes more crowded in the epi- 
thelial lining at the top of the Peyer’s patch; at other places, 
however, many more have emigrated into the epithelial border 
lining the crypts. These microphages are not only present 
near the attached ends of the epithelial cells, but they find 
their way, as Heidenhain? was the first to observe, even up to 
so high a level as the free border of the epithelium, and may 
fall into the intestinal cavity. I have been able to convince 
myself that these views were correct, by making numerous 
microscopical specimens of a recently killed guinea-pig or rab- 
bit’s intestinal contents, in which microphages are almost 
always found. 
So numerous are the microphages between the epithelial 
cells that, at first sight, they sometimes appear to have 
destroyed and taken the places of all the epithelial cells. 
1 Stohr, loc. cit. 
Heidenhain, ‘ Pfliger’s Arch.,’? Supplem. Heft, 1888; ‘Beitr. zur His- 
tologie und Phys. der Diinndarmsclileimhaut.’ 
