46 COLLECTED STUDIES IN IMMUNITY. 



the immune body. The immunity reaction occurs even under con- 

 ditions in which phagocytosis does not at all enter; and if, accord- 

 ing to the observations of Metchnikoff, somewhat less immune body 

 is produced after subcutaneous injections than after equal injections 

 peritoneally, this may be explained as follows: In consequence ctf 

 the slower absorption from the subcutaneous tissues, fewer cells- 

 come into contact with the group of the erythrocytes which excites 

 the immunity reaction before an excess of immune body is thrust 

 off by these cells into the blood. This immune body, of course, 

 prevents any further combination of the group in question with other 

 cells. 



To what extent the phagocytes are concerned in the production 

 of immune bodies must be determined separately in each case. No- 

 definite conclusions can be drawn from the experiments of Metchni- 

 koff on guinea-pigs with goose blood-cells, for at no time did the 

 organs of the specifically treated guinea-pigs show a stronger glob- 

 ulicidal action than those of normal animals, although such an 

 increase in haemolytic power was exhibited by the blood serum. But 

 the observation has been made that even in normal animals the 

 organs rich in macrophages are able, in contrast to other tissues, to- 

 dissolve goose blood-cells, and this observation is well adapted 

 in this case to support the assumption of a special significance of 

 the phagocytes for this function. However, that organs rich in 

 macrophages effect haemolytic action is not necessarily the case. For 

 example, the spleen of a guinea-pig (1 grm. finely crushed spleen 

 suspended in 1 c.c of an 8 p. m. NaCl solution), in contrast to the 

 blood serum of the same animal is not globulicidal for cattle blood. 

 Considering the large number of immune bodies, it will surely 

 often occur that the phagocytes are preeminently concerned in the 

 production of the immune body, especially since these cells frequently 

 come into intimate relations with the injected substances. On the 

 other hand, it is extremely improbable that the phagocytes alone 

 produce immune body. After all that has been said we shall have 

 to bring this production into relation with the general conditions 

 of nutrition. The most varied cells, according to the kind of side- 

 chains they possess and the affinities thereby brought about, are 

 probably able to produce immune body. 



Like the closely related antitoxic immunity reaction, the globu- 

 licidal and bactericidal reactions rest on a chemical process the 

 course of which is best explained on the basis of the side-chain theory. 



