1280 
hours and it may be shown that the luminosity of Ph. phosphoreum 
during this period is greatly intensified by glucose. Hence the very 
same argument which leads us to consider the alcohol function of the 
necrobiotic yeast-cell as an enzyme action, caused by one or more 
enzymes, called zymase, holds likewise with regard to the connection 
between phosphorescence and its factor or factors the luciferase. 
The still unknown “luciferine” which, as said, can result in the 
ease of Ph. phosphoreum from glucose, is the natural analogon of 
the “glucose-phosphoric-acid ester”, i. e. the substrate or enzymo- 
teel of the zymase. 
The necrobiotic yeast-cells have lost their semi-permeability, as 
shown by the ease wherewith they are dyed by methylene-blue, 
their power of reproduction and certainly the motility of their proto- 
plasm, whence they are considered as dead by several investigators. The 
same is probably the case with the necrobiotic luminous bacteria ; 
but change of permeability could not be stated, since also in the 
condition of normal life they have a great affinity for pigments. 
I venture to think that the loss of the above properties when based, 
as is supposed, on the becoming inactive or on the destruction of 
the more sensitive heredity units or enzymes, can quite well go side 
by side with the continued activity of another part of the protoplasm, 
so that then it cannot be said that the cell is “dead” in the same 
sense as when all its functions are destroyed. The importance of 
this view is obvious if we bear in mind that the theory of the units 
of heredity consists in the very supposition that from their com- 
bination energies and activities may arise strange to the units 
separately. The demonstration of the properties to be ascribed to 
special factors and of those due to the co-operation of two or more 
factors is the chief subject of the heredity researches of to-day 
and the difficulties met with are well known. That the enzyme theory 
will here be useful is obvious. 
About irritability I need not be long here, as for the lower 
immotile microbes this conception is only then based on observable 
facts if we think it coinciding with the power of metabolism and 
of reproduction. 
In this connection 1 call to mind that the peculiarity of actions 
caused by stimuli, consists in their showing an optimum for certain 
intensities of these stimuli, which is also the chief character of enzyme 
action. So the influence of temperature and of different concen- 
trations of poisons on the process of cell division and on that of 
amylolysis by diastase is analogous, and this is of course one of 
the best evidences for the correctness of the enzyme theory. 
Se eee ee 
