Blood Fluids in Intracelhdar Digestion. 



341 



completely digested during the succeeding 3| hours the phagocytic mixtures 

 were incubated. 



When the figures given by the films made from the samples taken from 

 tube 2, which contained heated serum, are examined, it is found that, instead 

 of the number of bacilli per 100 leucocytes diminishing, there is a steady 

 increase until, after the incubation of this tube had continued for four hours, 

 the number of organisms found to be ingested in 100 leucocytes approximated 

 to the number ingested through the action of the unheated serum in 

 15 minutes. 



Further, even after incubation had continued for four hours the bacilli 

 lying in the leucocytes showed practically no signs of digestion. 



Summary and Conclusions. 

 These experiments showed that, as regards the particular bacteria and red 

 blood corpuscles, and also as regards the blood fluids used in carrying them 

 out : — 



1. The blood fluids have the property of influencing the digestion of such 

 bodies as red blood corpuscles and bacteria taken up by the leucocytes. 



2. This action of the blood fluids is quite independent of the opsonic 

 action, this being shown by the fact that intracellular digestion may be more 

 marked as the result of the action of a serum of lower opsonic power than of 

 a serum of much higher opsonic power. 



In these two conclusions the author is in complete agreement with the 

 conclusions drawn by Eosenow. 



3. The power of the blood fluids to prepare such bodies as red blood cells 

 or bacteria for digestion by solutions such as trypsin and leucoprotease, or by 

 the digestive fluids which are secreted after such bodies 1 are ingested by the 

 leucocytes, is not, as stated by Eosenow, due to stimulation of, or an action 

 on the leucocytes, but is due to a direct action on the bacteria, or, as the 

 case may be, the red blood corpuscles. This is demonstrated by those 

 experiments in which the red blood corpuscles or bacteria, after being 

 brought in contact with fresh serum, which was subsequently removed, 

 were found to be digested by solutions of trypsin or leucoprotease, solutions 

 which had been previously shown to be quite without action. 



4. Heating the serum to 60° C. destroys the property of the serum to 

 prepare such bodies for digestion, at any rate in the case of normal serum. 



5. It is proposed to name this property of the blood fluids the " protryptic " 

 power of the serum, seeing that it prepares such bodies as red blood 

 corpuscles and bacteria for solution by the digestive fluids secreted by the 

 leucocytes or by solutions of trypsin. 



