404 



Dr. E. W. A. Walker. 



[May 16, 



Table III. — Showing the Beactions of certain Streptococci at Different Dates 

 after continued Cultivation in Stab Agar. 



Streptococcus. 



Date of testing. 



Milk clot. 



Saccharose. 



§ 

 1 



Eaffinose. 



a 

 | 



Salicin. 



Mannite. 



Number of changes. 



L 



June, 1908 



+ 





































+ 









! 







4 





y, 



+ 







+ 













P 



June, 1908 



+ 







+ 



+ 



























+ 









+ 







2 





7, 









+ 



+ 











2 



& 



June, 1 908 





+ 



+ 









+ 



+ 

























3 







+ 



+ 





+ 





+ 











M 



June, 1908 



+ 







+ 

















„ 1910 







+ 



+ 

















2 













+ 















3 



V 





+ 



+ 























„ 1910 



















+ 







4 











+ 



+ 







+ 







3 



E 



August, 1910 















+ 





+ 







November, 1910 







+ 















2 





January, 1912 





+ 







+ 



+ 



+ 



2 



Stability of the Beactions. 



The evidence for and against the stability of tS-ordon's test reactions may 

 now briefly be summarised. 



In bringing out the tests originally Gordon stated (1905, 1) that he had 

 found on repeating the tests three times over that each of the ten 

 streptococci responded on each subsequent occasion to each test in the 

 same fashion as it had done in the first instance." He also wrote as 

 follows (1905, 6) : " On several occasions I have re-examined a streptococcus 

 in the differential tests after it had been in culture for periods up to a 

 fortnight* and up to the present time I have always found that such 

 streptococci respond to the test in exactly the same manner as when first 

 isolated." He also re-examined 11 different streptococci after one passage 

 through the mouse, and found variation in two cases only, affecting one 

 reaction in each case. These results he regarded as " reassuring " in relation 

 •'* The italics are mine. — E. W. A. W. 



