Resorption of the formed elements 73 



partly upon the more active digestive power of the leucocytes of 

 Fishes. 



As the result of several injections of guinea-pig's blood into the 

 peritoneal cavity of Cyprinus, the peritoneal fluid acquires new 

 properties 1 . If, a fortnight after the first injection, a little of the 

 peritoneal exudation in the gold-fish be withdrawn, it is found that 

 a drop of the serum which floats on the surface produces, almost 

 immediately, well-marked agglutination of the red corpuscles of the 

 guinea-pig, this being soon followed by the rapid solution of these 

 red blood corpuscles in the fluid. This new property, which does not 

 exist in the untreated fish, also makes its appearance in the blood 

 serum of Cyprini treated with guinea-pig's blood. The experiment 

 is very successful at a temperature of 18 19 C. 



As the solution or lysis of the red blood corpuscles in the serum 

 is exactly like that which takes place within the leucocytes of 

 Cyprinus, we are justified in assuming that, in both cases, it is 

 produced by the same substance. And, since the solvent or haemo- 

 lytic power of the serum is only acquired as the result of the 

 intracellular digestion of the red blood corpuscles by the leucocytes, 

 it is probable that the solvent substance represents the intracellular 

 ferment derived from the leucocytes. 



The subject we have just broached is of fundamental importance 

 in connection with the study of resorption and of the phenomena of 

 immunity dependent upon it. It is necessary, therefore, that we 

 should go more fully into its analysis. With this object we must first 

 review the processes that go on during resorption in the higher 

 animals and continue our examination of the changes that injected [79] 

 or extra vasated blood undergoes in various positions of the organism. 



This study is rendered comparatively easy for us by the numerous 

 researches that have been carried out by pathological anatomists for 

 the purpose of ascertaining the fate of effusions or extravasations of 

 blood so frequently met with in disease. It has long been known that 

 in subcutaneous, cerebral and other haemorrhages, or in hepatised 

 lungs, there are found in the escaped blood a great number of cells 

 containing red corpuscles. As was mentioned in the preceding chapter, 

 these cells were evidently amoeboid cells that had ingested red blood 

 corpuscles. To Langhans 8 especially we owe a detailed study of the 



1 I have ouly been able to discover the haemolytic property of the serums of 

 Cyprinus after the third injection of guinea-pig's blood. 



2 Virchow's Archiv, 1870, Bd. XLIX, S. 66. 



