igo BOTANICAL GAZETTE [march 



from alcohol when it is given together with the esters. This would 

 seem to argue against the direct absorption of ethylidene by the proto- 

 plasm or cell constituents. 



Another possibility to be considered is the oxidation of alcohol 

 to acetaldehyde or even to acetic acid. This view becomes the more 

 probable on account of the ease with which alcohol is known in many 

 instances to be oxidized by organisms. This view would perhaps 

 explain also the increased stimulation of nitric acid over hydrochloric 

 acid, on the basis of the oxidizing power of nitric acid. Oxidation to 

 acetic acid, if it takes place at all, does not proceed to such an extent 

 that the acid accumulates in the cultures. 



To determine whether acetic acid was accumulated in the cultures, 

 10 flasks, with alcohol as an organic food, were inoculated in the usual 

 way. After a vigorous growth took place, the culture solution was 

 poured off, and after rinsing was replaced by a 0.3 GM. solution of 

 alcohol. After further 6 days this liquid was tested for acetic acid, 

 but none could be detected. Duclaux also was unable to observe 

 the formation of acetic acid from alcohol by Aspergillus, but mentions 

 the fact that alcohol was assimilated with the intermediate formation 

 of oxalic acid. I was unable to show the presence of oxalic acid in 

 the cultures of Penicillium, nor is it likely that this is formed. If 

 alcohol is assimilated by way of acetic acid the oxidation takes place 

 entirely within the cell. 



Another fact gained from the ethyl acetate cultures (table X) 

 speaks against the oxidation of alcohol to acetic acid. From the 

 general principles resulting from the work on selective power or 

 organisms by Pasteur, Duclaux, and Pfeffer, we know that when 

 two foods of different nutrient value are given to a plant, the one 

 most readily assimilated is used, often to the exclusion of the other. 

 Although the experiments with ethyl acetate have not been carried 

 as far as might be desirable, there is some evidence that acid accumu- 

 lates in the cultures, consequently that the alcohol radicle is more 

 readily absorbed than the acid radicles. This, it would seem, would 

 not take place if it was first necessary to oxidize the alcohol to acetic 

 acid. If any oxidation takes place it is probable that this stops with 

 acetaldehyde, from which the formation of sugars can proceed. It 

 would then be probable that the acetic acid in all cases was reduced 



