314 STUDIES IX IMMUNITY. 



a certain part of their salts and it is perfectly evident that these 

 salts in the course of their diffusion from within the blood cells will 

 be more abundant in the pericorpuscular zone near the corpuscle 

 than in the fluid between the corpuscles at a relatively considerable 

 distance from the corpuscles. And so Mangin and Henri think that 

 colloidal substances mixed with a suspension of corpuscles will 

 by preference be precipitated in the more concentrated pericor- 

 puscular zone. 



Following this first stage, a second would occur, during which the 

 particles of colloidal substances that have been flocculated about 

 the corpuscles by means of the endocorpuscular salts would col- 

 lect into masses and drag the corpuscles with them; hence would 

 result the formation of masses composed of colloids and corpuscles. 



According to this theory the agglutination of red blood cells 

 by colloidal substances depends on a preliminary precipitation of 

 these colloids about the corpuscles by means of the diffused electro- 

 lytes from within the corpuscles. The corpuscles remain quite 

 passive during the entire phenomenon and are simply brought 

 together by means of the collection of particles of colloidal sub- 

 stances that have been precipitated about them. 



We do not believe that the phenomenon of agglutination of 

 corpuscles by colloids should be interpreted in this way; we think 

 rather that the agglutination is due to a direct action of one of 

 these elements on the other.* We think, indeed, that we are justi- 

 fied in applying the conclusions drawn from the facts we have 

 observed with chemical precipitates to the agglutination of cor- 

 puscles by colloids. According to the opinion of Bredig f these 

 two substances are of the same order and differ from one another 

 simply in a variation in size of their particles. This opinion indeed 

 is shared in so far as the present phenomena are concerned by 

 Landsteiner and Jagic $ and by Mangin and Henri. § 



It is to be noted in the first place that the colloids studied by these 

 latter authors are very susceptible to flocking by electrolytes; 



* It is evident that there is no dispute about the well-known action of salts in 

 the phenomenon of agglutination in general; we are dealing here simply with the 

 function attributed by Mangin and Henri to the salts that have diffused from the 

 red blood cells on their agglutination by colloids. 



t Bredig, Anorganische Fermente. 



% Landsteiner et Jagic, Munch, med. Woch., No. 27, 1904. 



§ Mine. Girard-Mangin et V. Henri, Soc de Biol., No. 19, 1904. 



