510 SELMAN A. WAKSMAN 



belongs to the group of black Aspergilli which have not been 

 well differentiated before. 



Aspergillus ochraceus Wilhelm. A preliminary description of 

 this organism has appeared in another place (Waksman, 1916), 

 as C. 19. The organism revealed peculiar metabolic processes 

 and a number of investigations were conducted with it. 



Aspergillus fuscus Schiemann. 



Aspergillus clavatus Desmazieres. 



Citromyces glaber Wehmer. 



Penicillium chrysogenum Thom. 



Actinomyces griseus (Krainsky) Waksman and Curtis. 



Actinomyces violaceus-ruber Waksman and Curtis. 



Actinomyces sp. 101 (virido-chromogenus?) Krainsky Waksman 

 and Curtis. A full description of this organism will soon appear. 



Actinomyces californicus Waksman and Curtis. 



METHODS USED IN THE INVESTIGATION 



The organisms were growTi on Czapek's solution composed as 

 follows : 



NaNOs 2.0 grams 



K2HPO4 10 gram 



KCl 0.5 gram 



MgS04 0.5 gram 



FeSOi . 01 gram 



Cane sugar 30.0 grams 



Distilled water 1000 cc. 



In addition another medium was made up by substituting 20 

 grams peptone for the 2 grams NaNOs per liter. This medium 

 is called Peptone-Czapek solution. The media were distributed 

 in 100 cc. portions in 200 cc. Erlenmeyer flasks, plugged and 

 sterilized for fifteen minutes at 15 pounds pressure. The flasks 

 were then inoculated and incubated at 28°C. At the end of the 

 proper incubation period, the cultures were filtered through No. 

 584 folded Schleicher & Schiill filters. The filtrate was used for 

 the study of the exoenzymes; while the mycelium was washed 

 with distilled water, and then treated by the acetone method, 

 as used by Dor (1910), Scales (1914), and others. Twenty 



