F. F. Blackman. 
26 
on this carbohydrate reserve of the cells giving rise to alcohol and 
C0 2 in small quantities even in the absence of added sugar. As 
regards this process Albert has shown that neither the glycogen nor 
the enzyme can diffuse at all out of the dead protoplast. In addition 
there are no doubt other enzymes at work in these killed cells, 
accelerating other metabolic changes just as in life. 
Though these cells have no power of budding or growing or, 
presumably, of increasing their substance, they can still hardly be 
called quite dead with so much of their metabolic machinery still 
functioning, and German writers distinguish this condition as 
“abgetoteten” (killed) as opposed to “abgestorben” (dead of a 
natural death). 
A very similar state of things has been described by Beijerinck' 
for the Urococcits which converts urea into ammonium carbonate. 
The change is attributed to an enzyme, urea’se, which continues to 
function after the bacteria have been killed with alcohol. Here 
also the enzyme does not diffuse out of the cell, killed or alive. 
More recently Stoklasa 2 has shown that the characteristic 
enzyme of yeast, zymase, also occurs in the cells of the higher 
plants, perhaps universally. It can be separated and made to 
ferment sugar in vitro by expressing the sap from the fresh parts 
by a pressure of 300 atmospheres. This extract is then precipi¬ 
tated with a mixture of alcohol and ether. The precipitate is 
quickly dried in vacuo and then keeps well. Whenever it is added 
to a sterile solution of glucose, active formation of alcohol and 
carbon dioxide at once takes place and lasts for a varying number 
of days. 
It has long been known that when the higher plants are kept 
deprived of oxygen, they produce alcohol and C0 2 , just as yeast 
does, but the process here has the special name of intra-molecular 
respiration. It is now clear that in both cases we have a splitting 
up of sugar by the same enzyme, zymase. 
Godlewski 3 has further shown that intact Lupine seeds will, 
during their germination, cause the splitting of glucose when kept, 
quite sterile, submerged in a sugar-solution in the complete absence 
of oxygen. Not only do the scanty carbohydrate reserves of the 
seeds disappear but the sugar from outside is acted upon by the 
zymase of the seeds, and alcohol and CO s are formed in the 
calculated proportions. 
1 Ccntrlbl. f. Bakt. VII., 1901. 
* Ber. deut. chem. Ges. XXXVI., 1. Jan. 1903, Ccntrlbl. f. Bakt. 
XIII. 1904, Pfluger’s Archiv. Cl., 1904, etc., etc. 
8 Bull. Acad. Sciences, Cracovie, March, 1904. 
