The suspensions of organ cells were now introduced into small test tubc.% 

 inoculated with two loopfuls of a 24-hour broth culture of a non-virulent 

 streptococcus, and two loopfuls were plated at intervals. The colonies 

 that developed in each plate were carefully estimated and the results 

 are shown in Table 4. In no instance did the suspension of organ cells 

 have an inhibitive effect on the multiplication of the streptococci, but 

 on the contrary the organisms multiplied more rapidly in these suspen- 

 sions than in either the serum or the defibrinated blood alone. If, how- 

 ever, bone marrow was added to the defibrinated blood or serum, the 

 number of streptococci in these tubes was greatly diminished during the 

 first three to five hours. 



These results agree with those found by Bail and Pettersson* in 

 their study of the mechanism of anthrax immunity in chickens, and show 

 that suspensions of organ cells from the guinea-pig possess no strepto- 

 coccidal power, except the suspensions of bone marrow. Suspensions 

 of marrow cells in defibrinated blood or serum kill large numbers of 

 avirulent streptococci, but that is not the case with suspensions in salt 

 solution. These results have also been obtained with suspensions of 

 rabbit's bone marrow. 



PHAGOCYTOSIS OF LIVING STREPTOCOCCI IN VIVO. 



It having been found that leucocytes ingest and destroy streptococci 

 in test tube experiments, the following experiment was made to show 

 that there is phagocytosis of living streptococci in the animal body: 



A guinea-pig was injected in the right pleura with 7 c. c. of 

 aleuronat suspension. Twelve hours later he was injected in tin's 

 pleura with 2 c. c. of an 1 8-hour glucose broth culture of a non- 

 virulent streptococcus, and two hours after this injection he was bled to 

 death. Several cubic centimeters of leucocytic exudate were now taken 

 from the right pleura, under aseptic precautions. Smears made with 

 this exudate contained no free streptococci, but many of the leucocytes 

 contained cocci in large numbers. 



Figure i is a photomicrograph of one of these smears showing 

 streptococci in the body of a leucocyte. 



Preparation of Slides. By means of a sterile, soft cotton swab a 

 small quantity of the exudate was now gently smeared on each of eight 

 agar-covered slides ; the slides were incubated in a moist chamber for 

 four to six hours, stained and examined under the microscope. The prep- 

 aration of these slides requires the following special technic. Three 

 ordinary clean glass slides and a heavy watch glass are placed in a large 



*Centnilbl. f. Bakt, 1903, XXXV, 102. 



