ZYMASES IN ANIMAL TISSUES 331 



animal economy have not only not been proved but are not 

 even probable. 



The author acknowledges that this is only his own sub- 

 jective impression, and desires to add that others who have 

 gone at length into this problem have arrived at a contrary 

 opinion. Thus Carl Oppenheimer does not look on the bac- 

 terial objection, even if it cannot be completely put aside, as 

 the real nucleus of the question. "Stoklasa found a satis- 

 factory reproduction of yeast fermentation in all its phases. 

 Where are the bacteria which are carrying this on? We are 

 aware, of course, that in bacterial fermentations alcohol 

 occurs as a more or less insignificant by-product. Either 

 Stoklasa 's alcohol findings are false when there is nothing 

 further to be said to the contrary; or they are correct and 

 in this case they cannot be referred to the action of bacteria. 

 That true yeast cells are present in Stoklasa 's ether-precipi- 

 tated extracts of tissues no one has, to the best of my knowl- 

 edge, as yet asserted. A priori it is much more probable 

 that the investigators following Stoklasa have not had the 

 same fortunate hand as he. ... Other sources of error 

 are in all probability to be apprehended in the antiseptics 

 employed; which perhaps may have so thoroughly elimi- 

 nated the bacteria so often called into question that the easily 

 affected zymase has also been destroyed by them. . . . 

 We have, in fact, here one of the most curious of spectacles, 

 one which only an exact research can afford on one side a 

 series of experiments published in fullest extent, with all 

 details, which always give the same result; on the other, 

 a list of reinvestigators who are unable to find anything and 

 who introduce into the field unsupported contradiction of 

 the experiments. As long as no one appears to show 

 . . . where the alcohol and lactic acid come from in 

 Stoklasa 's experiments his experiments are going to stand 

 like a rocker de bronze." 



Even as objective an observer as Hammer st en 11 con- 



11 O. Hammersten, Lehrb. d. physiol. Chem., 7th ed, 382, 1910. 



