16 



300 Erysipelas I ..... G30 64 



300 II 15000 800 14 4 



300 H;i 1100 41 8 



300 III 740 120 160 



300 IV 1650 480 150 



298 V 10400 3100 420 02 



I 1200 1080 960 



B104 II 96 30 13 



B104 IV 133 110 480 



300 Tonsillitis I 16000 620 34 2 



JB104 I 300 59 70 



300 II 1400 74 6 



300 Pneumonia 1 2600 3 



500 " II 600 5 



Serum 



300 Scarlatina VII 1500 3500 10000 



300 " XIV 1200 1400 1300 



300 Erysipelas II 670 760 7.".0 



300 III 700 1800 6<XIO 



300 " .V 3000 3500 5000 



B104 " V 190 360 1140 



In these infections the leucocyte count is usually somewhat increased, 

 and it seems that the streptococcidal power of the blood in vitro is 

 roughly proportional to the leucocyte count. That is, the higher the leu- 

 cocyte count the greater will be the streptococcidal power of the blood. 

 This is a general rule; to which there are, however, a few exceptions, 

 as will be pointed out later. The virulent organisms frequently multiply 

 in these bloods unless the leucocytosis is very high. In no instance could 

 a streptococcidal power of the serum alone be detected. It might be 

 objected that we are not dealing here with an actual destruction of cocci, 

 but that the decrease in the number of colonies on the plates is due to 

 adherence of the cocci to the leucocytes. This objection is ruled out 

 by the fact that the twenty-four-hour plates from tubes containing blood 

 with a high leucocytosis are very often sterile or nearly so. 



It has been thought possible that the serum during the course of an 

 infection which terminates favorably might acquire streptococcidal prop- 

 -erties for that particular race of streptococci which is responsible for 

 the infection, while at the, same time it had no such properties for other 

 races of these organisms. Three strains of streptococcus were, there- 

 fore, isolated from erysipelas patients and the serum of each patient 

 tested on the corresponding organism. All of the patients made a sat- 

 isfactory recovery, but at no time could streptococcidai properties be 

 demonstrated in their serum. The defibrinated blood, on the other hand, 



