TOL. | On Variation and Adaptation in Bacteria. So 
It will be noted that, after eight weeks of growth in inulin, L, S, and G 
gave identical reactions which only differed in respect of the milk-clotting 
from the reactions given by M after a fortnight’s growth in the same 
medium. The number and variety of the other changes which appeared is 
very striking. 
Mannite Test. 
An attempt was also made to teach the organisms, L, P, 8, G, M, V, H, to 
ferment mannite by growing them in the mannite medium. This was 
unsuccessful after four months’ trial, but is interesting as showing (Table VI) 
that although the mannite reaction itself refused to change, some of the other 
reactions were modified in some cases by the continued cultivation in mannite. 
The following is the protocol of the experiment :— 
L, P, 8, G, M, V, H, were grown from August 1 to October 1 as follows: 
Three days in mannite medium, sub-culture in ordinary bouillon one day, 
back to mannite medium for three days, and soon. No change of reaction 
had occurred by October 1. , 
The organisms were now grown three days in mannite anaérobically, 
one day in bouillon aérobically, back to anaérobic culture in mannite for 
three days, and so on. By October 15 all but G and H discharged the 
colour in mannite, but the blue colour returned on admitting air. This 
state. of things continued in the successive cultures until November 10, 
when G and H were abandoned. L, 8, P, V, M, were now grown in mannite 
Table VI.—Streptococci L, P,S, V and M. Showing the Changes of Reactions 
which had taken place at the end of the Mannite Experiment. 
2 | | 
8 3 8s | 
= Nn . | 5 ° 
3 Time of testing. = 2 ae Z 3 Sie |e 
a dat Te |) | Heer OUM Reet reel 
2 A) oe) en eee ee eee aes 
D Sl we reset eae i ee les reek eee 
L eT e e LOMO MR ata Geeeeee Saved ee co 0 0 + 0 0 0) 
2. After 4 months in mannite ...... CHO eo Of Oy eo 0 
EM leans 1910) Neer Us scene. Oy 08 er ecOny | Onna er kian@ 
2. After 4 months in mannite...... | Oo | O.y + @) OFF) eee CO O 
s Pero UTC OMOM vapcioncdecc ties sues oat 0 + + 0 0 aa gO 
2. After 4 months in mannite...... 10 + 0 O O 6) | 8) 2 
Vv ee MITCH NGO Ne. year Cw. se cvas'es On) Ons eo Our nO 1 0 
2. After 4 months in mannite...... lap steer 2? OW Waaets (0) 0 + |.0 i 
3 | | 
Wiesel: Tunis TOULO shal iscvoia<seoecvnsncde Oph. Se On Gilat tee tO 
2. After 4 months in mannite...... 0 0 + 0 0 + 0 1 
