BIOLOGY OF PNEUMOCOCCUS 59 



leates and immune serum on the lysis of pneumococci, Lamar 778 

 noted that the oleates rendered the cocci more susceptible to serum 

 lysis. In normal serum their action was incomplete, but in immune 

 serum there was no multiplication of the organism and lysis was 

 complete. As an explanation, Lamar suggested that the action of 

 the soap was exerted upon the lipoidal portion of the bacterial cell, 

 through which it was rendered more pervious to serum constitu- 

 ents and brought under their deleterious and dissolving influence. 



In another paper, Lamar 774 reported that sodium linoleate and 

 sodium linolenate killed and dissolved pneumococci more rapidly 

 and in higher dilutions than did sodium oleate. Furthermore, in the 

 experiments it was seen that blood serum inhibited the bacteriolytic 

 action of the unsaturated soaps, partly or completely, depend- 

 ing upon the quantitative ratio between serum and soap. Lamar 

 concluded that the action was probably caused in part by the 

 avidity of the unsaturated fatty acids for protein and not wholly 

 by their ability to dissolve lipids. 



In 1926, Falk and Yang 385 compared the solvent action of so- 

 dium oleate, sodium hydroxide, tribasic sodium phosphate, and 

 saponin on washed pneumococci, and learnt that all these sub- 

 stances in the concentrations tested, with the exception of saponin, 

 were as specific in their action as is bile. 



In another communication, Falk and Yang 384 described the influ- 

 ence exerted by certain electrolytes and non-electrolytes on bile- 

 solubility. Chlorides with monovalent cations when present in 

 relatively low concentrations inhibited the solution of washed pneu- 

 mococci by bile, but in higher concentrations possibly accelerated 

 solution. Chlorides with divalent cations acted in reverse fashion, 

 inhibiting more effectively in high than in low concentrations. Of 

 the anion series tested, sodium hydroxide and tribasic sodium 

 phosphate were cytolytic to pneumococci, whereas dibasic and acid 

 sodium phosphate, sodium sulfate, and sodium nitrate were not. 

 Peptone, gelatin, and ovalbumin appeared to inhibit cytolysis by 

 bile in the same manner as calcium or barium chloride. Falk and 



