1889-90.] Dr G. E. C. Wood on Enzyme Action. 
89 
had lost the power of liquefying the gelatine had also lost the 
faculty of forming their characteristic pigments.* This function 
was, however, much more easily lost than the enzyme function, for 
perfectly colourless cultures could be obtained, which nevertheless 
acted on the gelatine and milk, and it was evident that by properly 
graduating the agent brought to bear on the organism, the one 
might be lost without the other being appreciably affected. 
It has already been stated that Fliigge found that micro-organ- 
isms when grown in the absence of oxygen, appeared to obtain their 
food without the aid of enzymes, as they then ceased to liquefy the gela- 
tine. The most natural supposition is, that oxygen being necessary 
for the formation of the enzymes, when it is excluded, the proto- 
plasm reverts more or less to the primary form of digestion — that 
without enzymes. This may, in some cases, be the explanation, but 
there are a number of facts which tend to show that in some cases 
under anaerobiosis the products of the organism are different from 
those which occur under aerobiosis. This has led Hueppe and 
Brieger to suggest that the metabolism of the organism under 
aerobiotic and anaerobiotic states may be different, these two 
being entirely different adaptations of the protoplasm. On this 
view, under anaerobiosis , they do not liquefy the gelatine, because 
they then take their food in a different way from what they 
do under aerobiosis. If this conception should, at first sight, 
appear rather fantastic, I must refer to certain facts which indicate 
that such organisms may have an adaptation to even so impal- 
pable an agent as light. Prove f found that Streptococcus ochroleukus 
produced its yellow pigment only when exposed to diffuse daylight, 
while Scholl states that Bacterium mycoides roseum formed its red 
pigment in darkness only. There is no escape, here, from the con- 
clusion that these two organisms have developed their pigment func- 
tion under different conditions, which alone permit of its exercise, 
a result in perfect harmony with the beautiful researches of Engel- 
* Staphylococcus aureus , when obtained from an abscess, must frequently be 
cultivated for some time before the pigment faculty returns ; other organisms 
when exposed to the action of the tissues exhibit a temporary loss of the 
enzyme function. In both cases this may be attributed, in part to an adapta- 
tion to the conditions present in the animal organism, and in part to the 
attenuating influence exerted by the cells. 
t Cohn’s Beitrage zur Biol. d. Pflanzen , Bd. iv., 1887. 
