82 Chapter IV 



ingested. Little by little the devoured coiiniscles are digested within 

 the phagocytes. The haemoglobin diffuses into the contents of the 

 macrophage through the stroma, which has become permeable ; the 

 nucleus of the ingested red corpuscle also becomes stained by 

 the haemoglobin. Part of this colouring matter is excreted by the 

 [88] phagocyte. The body of the red corpuscle is pretty soon digested, 

 but the nucleus, impregnated with haemoglobin, persists for a much 

 longer period. It divides into several fragments, recognisable by their 

 yellow colour, and in certain cases these remnants of red corpuscles 

 may be met with for weeks in the interior of the macrophages. These 

 macrophages do not remain permanently in the peritoneal fluid. 

 Some (3 — 4) days after injection the lymph of the peritoneum 

 contains only leucocytes that have newly come up and which 

 contain neither red corpuscles nor their remains. We must open 

 the guinea-pig to find any macrophages that have devoured red 

 corpuscles. They are to be met with in large numbers in the 

 glandular portion of the omentum, in the mesenteric glands, in the 

 liver and in the spleen. Tliey are fairly easily recognised by the 

 characteristic aspect of the d4hris of the red blood corpuscles. 

 Having devoured the red corpuscles the macrophages leave the 

 peritoneal fluid and the digestion is comi)leted in the positions 

 just mentioned. In the liver they are seen as large mononuclear 

 cells often with highly developed processes. In this condition they 

 remind one of Kupffer's stellate cells — a fact that suggested to me 

 the idea that these elements are nothing but white corpuscles which 

 have immigrated into the vessels of the liver. 



Following up the fate of the macrophages that have resorbed 

 the red blood corpuscles, we find them in the large hepatic vessels, 

 in the vena cava and even in the blood of the heart. But in 

 these latter situations they contain merely a few scarcely recognisable 

 traces of their prey. These phagocytes, which left the blood during 

 the inflammation that followed the injection of red corpuscles of 

 the goose, re-enter it, having fulfilled their function, during the final 

 period of the resorption. This resorption must undoubtedly be 

 regarded as an intracellular digestion. When we compare the 

 essential phenomena taking place inside the macrophages containing 

 red blood corpuscles with those we have described in the intestinal 

 phagocytes of the Planarians or Actinians after a meal, the analogy 

 between the two becomes very apparent. In both cases the red blood 

 corpuscles undergo a marked change which results in a diftusion of 



