218 



Scientific Proceedings (115). 



Because of the similarity between these observations and the 

 phenomenon of d'Herelle, the following experiments were under- 

 taken with the hope of obtaining from vaccinia a typical bacteri- 

 ophage for staphylococci. 



Several agar slants were seeded with untreated fresh green 

 vaccinia pulp. The growth, consisting of Staphylococcus albus, 

 Staphylococcus aureus, and B. coli, looked normal in all tubes but 

 one, in which a few small, clarified areas were found. 



Filtrates obtained from subcultures of these clarified spots 

 were found to possess a marked inhibiting and dissolving action on 

 the growth of staphylococci, and this lysis could be carried on in- 

 definitely from one culture to another. 



Staphylococcus is, therefore, the first Gram-positive bacterium 

 for which an observation of transmissible autolysis has been made. 

 Attempt to extend the lysis to other cocci has thus far been 

 unsuccessful. 



As has already been observed for other species, great varia- 

 tions in sensitiveness exist not only among different strains of 

 staphylococci — certain ones remaining unaffected — but also be- 

 tween different organisms of a single strain, a few individuals 

 usually being able to resist solution. 



If a partially dissolved culture of staphylococcus is streaked 

 on agar plates, it is found that in the first streak, where the lytic 

 broth is spread abundantly together with the cocci which are 

 still alive, the growth is poor, irregular and glassy. In the sub- 

 sequent streaks, the colonies are less irregular, and finally become 

 normally round and opaque. A round colony, transplanted, gives 

 only round colonies, while an irregular colony gives colonies which, 

 irregular in the first streaks, become less irregular and finally 

 round in the following streaks. 



In agreement with the observations described by Kuttner 1 

 for typhoid bacilli, and with our own observations on B. coli, an 

 irregular colony was found to be lysogenic, a regular colony non- 

 lysogenic. 



In the course of our previous studies on coagulation of blood 

 we observed a coagulant effect exerted by staphylococcus on all 

 kinds of non-spontaneously-coagulable blood plasma (oxalated, 



1 Proc. Soc. Exper. Biol, and Med., 1921, xviii, 158. 



