270 SCIENCE PROGRESS. 



and the enzyme are situated in different cells, being brought 

 into contact in consequence of the wound. This suggestion 

 seems, however, unnecessary, as the oxidases have been 

 shown to work upon the aromatic bodies they attack only 

 in the presence of oxygen. The access of the latter is only 

 possible when the surface of the pulp is exposed. 



ANIMAL OXIDASES. 



The oxidases so far described have been discovered 

 chiefly in the vegetable kingdom. It has been mentioned 

 above that recently an enzyme which has similar properties 

 to laccase is stated by Fieri and Portier (14) to exist in the 

 gills, palpi and blood of certain molluscs. They have pre- 

 pared it by methods similar to those of Bourquelot and 

 Bertrand, and they find it oxidise various aromatic bodies 

 in the presence of oxygen, neither the enzyme nor the gas 

 acting in the absence of the other. 



Oxidative processes have long been known to take place 

 in blood when shed and exposed to the air. Claud Bernard 

 first pointed out that under these conditions sugar dis- 

 appeared, and his results have been confirmed by many 

 subsequent observers. Only within recent years, however, 

 has it been suggested that this disappearance of sugar is due 

 to an enzymic action, but this view is now put forward, by 

 several observers. 



The action was examined with some completeness by 

 Seegen (26) in 1892, who found that the disappearance of 

 the sugar is not influenced by the presence of chloroform, 

 which prevents the action of living cells and micro-organ- 

 isms, but does not inhibit the work of enzymes. Seegen 

 found that the exclusion of bacteria by other means does not 

 prevent the glycolysis, and argues in favour of the presence 

 of a sugar-destroying enzyme. The destruction is hindered 

 by a low temperature, occurs very rapidly at 39-40° C, and 

 is inhibited at 54*5° C. 



Lepine (27) made some experiments with the pancreas 

 of the dog, which led him to the view that the secretion 

 of a glycolytic enzyme is one of the functions of that 



