294 Chapter IX 



a phenomenon which is associated with the development of the 

 protective power. The most simple explanation of these facts is 

 that the micro-organisms injected into the peritoneal cavity and soon 

 afterwards seized by the phagocytes (for the most part by the micro- 

 phages), are carried to the phagocytic organs, particularly the spleen, 

 lymphatic glands, and bone-marrow. In those animals whose spleens 

 are left intact a large number of these microphages loaded with 

 micro-organisms make their way into this organ, a fact confirmed by 

 direct observation. When the spleen is removed the microphages 

 must necessarily betake themselves to other phagocytic organs. As 

 the micro-organisms undergo intracellular digestion in the phago- 

 cytes, it is very difficult, if not impossible, to follow them for any 

 length of time after they have been ingested, but the analogy with 

 the phenomena of the resorption of red blood corpuscles, described 

 in Chapter IV, justifies us in concluding that in the case of micro- 

 organisms matters go on in much the same way. These organisms, 

 seized at the seat of inoculation by the phagocytes, are transported 

 by these cells, in their peregrination through the organs, into the 

 general circulation. The interpretation I have just given has been 

 accepted by Deutsch. 



This observer wished also to come to some conclusion as to the 

 origin of the agglutinative property so well developed in the fluids 

 of animals inoculated with the typhoid cocco-bacillus. He did not 

 [309] succeed in solving this question, but he was able to demonstrate the 

 undoubted difference between this property and the protective power. 

 The facts brought forward by Deutsch must, therefore, be ranged 

 alongside the many others, reported on above, which demonstrate in 

 the most conclusive fashion that these two powers of the body fluids 

 are essentially distinct. 



Such concordant results obtained by all investigators who have 

 studied the origin of the protective power warrant the conclusion 

 that it is the elements of the phagocytic organs, that is to say, the 

 phagocytes themselves, which produce the protective substance. But 

 it will be asked : Can we therefore accept the fixative substance or 

 fixative as being derived from the same source ? When the ex- 

 periments I have just summarised were carried out the fixatives 

 were not as yet sufficiently known and were confounded with the 

 protective substances. Nevertheless, there can be no doubt as to 

 what the answer to the question just put must be. In the account 

 of the experiments of Pfeiffer and Marx we find very precise state- 



