BIOLOGY OF PNEUMOCOCCUS 61 



Avery found, furthermore, that when suspensions of pneumococci 

 were cooled at 0° — a temperature at which the rate of enzyme ac- 

 tion is greatly retarded — the organisms went into solution rapidly 

 when sodium desoxycholate was added, and the process was not ac- 

 companied by lipolysis or proteolysis. These authors concluded 

 that it did not seem probable, therefore, that the bile solution of 

 Pneumococcus was identical with the phenomenon of autolysis as 

 ordinarily understood and measured. Unpublished work by Dubos 

 would, on the contrary, seem to indicate that bile solution occurs 

 only under conditions when cell ferments remain active. 



There can be no doubt, however, that the intracellular enzymes 

 may act as adjuvants in cell dissolution. The action of extracts of 

 living pneumococci in dissolving dead pneumococci (Avery and 

 Cullen 41 ) with an increase in non-coagulable and amino nitrogen 

 and in ether-soluble fatty acids (Goebel and Avery 520 ) favor this 

 view, a view which has received additional support by the experi- 

 ments of Wollman and Averbusch, 1535 " 36 who were able to cause 

 bile solution of killed non-soluble, virulent, and avirulent pneumo- 

 cocci by the addition of a small amount of a living, avirulent cul- 

 ture to the bile-culture mixture. This phenomenon they called 

 autolyse transmissible. 



Atkin 29 made the original observation that organisms compris- 

 ing the papillae which frequently arise as secondary growths on 

 autolyzed colonies of pneumococci on serum agar were quite in- 

 soluble in bile. It was evident that the organisms of which the 

 papillae consist were devoid of autolysin since they showed no 

 tendency to undergo dissolution or self-digestion even after several 

 weeks of incubation. The organisms thus derived, when subcultured 

 on fresh serum agar, regained autolytic power and at the same 

 time became bile-soluble. Atkin made the statement that "bile solu- 

 bility of pneumococcus is due to an acceleration of the normal 

 autolytic process by this substance, and that no solution of the or- 

 ganism occurs except in the presence of the autolysin." 



Another observation which contributed to the question was that 



