BOTANICAL GAZETTE 



[march 



tically all the spores had germinated and had produced germ tubes 

 50 to 100 fi long. This is clear proof that the potassium ethyl sulfate 

 is not poisonous in the concentrations used, but also that it is not a 

 suitable source of carbon. This is more fully brought out in table VI- 

 The cultures with potassium ethyl sulfate behaved as before, while 

 those with sulfate to which alcohol was added gave a yield comparable 

 with that obtained when alcohol alone was given. These cultures, 

 like the alcohol cultures, remained pure white and produced no 

 spores. 



Ethyl nitrate in various concentrations ranging from o.46 gm per 

 5o cc to o.9i gm per 5o cc proved absolutely valueless as a source of 

 carbon, although like potassium ethyl sulfate it did not inhibit germi- 

 nation at these concentrations. In a series in which the ethyl nitrate 

 was given as the sole source of carbon and nitrogen, no growth took 

 place. Neither is the fungus able to break up the nitrate by means 

 of energy derived from alcohol, as table VIII shows, for the addition 

 of ethyl nitrate failed to produce an increase of yield over pure alcohol. 

 On the contrary, the higher concentration depressed the yield, showing 

 that ethyl nitrate is mildly toxic. This is also shown by the fact that 

 spores in cultures with ethyl nitrate germinated two to three days 

 later than the alcohol cultures. The depression of yield may be due 

 partly to the delay in germination, and partly to the toxic effect of the 

 nitrate. The cultures produced no spores. 



Ethyl acetate. — While the esters of alcohol with mineral acids 

 proved valueless as a source of carbon for Penicillium, the ethyl ester 

 of acetic acid in dilute solution is an efficient source of carbon; but 

 in stronger solutions it becomes a poison, as appears from tables IX and 

 X. The mineral solution used here was of the same composition as ; 

 in the alcohol cultures. 



TABLE IX 

 Each flask received o.22gm CH 3 COOC 2 H s = o.o5 GM. per liter. 



