sua cs sala 
1905] BARNES—THE THEORY OF RESPIRATION 93 
STEPANEK has reached the same conclusion,'' and Maz&"? has found 
acetic acid as an intermediate product in alcoholic fermentation by 
a different yeast. The interest of the discovery that inactive ethy- 
lidene lactic acid is the intermediate substance in this process of 
fermentation lies in the fact that one of the two acids of which that 
is composed namely, d-ethylidene lactic acid, or sarcolactic acid, 
is formed as a product of respiration when proteids break down in 
the working, fatigued, or dying muscle. FLETCHER observed this 
as a more prominent product of contracting muscles than carbon 
dioxid itself. Thus a regular product of fermentation is also formed 
in the ordinary course of respiration. 
The analogy between anaerobic respiration and fermentation had 
been suggested early—even by PAstEUR—and has thus been growing 
closer with each added bit of knowledge But the precise way in 
which the destruction of the living substance went on in anaerobic 
respiration was still unknown. Fermentation had been shown to 
be due to an enzyme. Was anaerobic respiration also due to an 
enzyme ? 
Of course, enzymes are known to be present in a great many of 
the parts of plants, and the oxidizing enzymes seemed to be the sort 
to be sought. But none seemed to answer the conditions. At last, 
however, the object appears to have been attained. STOKLASA, in 
a series of papers published in various journals,*’ but all dealing with 
the same general problem, declares he has found in various tissues 
of animals, and in considerable number of plants, an enzyme analo- 
™ Ueber die aerobe und anaerobe Atmung der Eier. Centralbl. Physiol. 18: 
188-205. 1904. : 
72 Utilization du carbone ternaire. Ann. Inst. Pasteur 18:277-303. 1904. 
13 rere Identitat anaerob. Atmung u. Garung. O6esterr. Chem. Zeit. 
1903. (Not se 
STOKLASA, eek and VirEK: Der anaer. Stoffwechsel der héh. Pfl. und seine 
Bezeihung z. alcoh. Garung. Beitr. z. Chem. Physiol. u. Path. 3:4 c 
ASA and Cern¢: Isolierun| ng des die anaer. Atmung der Zelle der héh. 
org. Pfl. und Tiere bewirk. Enzymes. Ber. Deutsch. Chem. Gesells. 36: 622-634 
1903. 
——: Ueber die anaer. Atm. der Tierorgane u. iiber die Isolierung eines garungs- 
erregenden Enzymes aus dem Tie erorganismus. Zentralbl. Phy siol. 16:652-658. 
1903. 
Semen! Ueber die Atmungsenzyme. Ber. Deutsch. Bot. Gesells, 22: 358-361. 
4. 
