344 LON A. HAWKINS AND NEIL E. STEVENS 
appearance, their solubility in ether and alcohol and the fact that they 
were practically insoluble in water, were very similar. No crystalline 
compound was obtained by this method. 
An acetyl derivative was prepared from this yellow pigment by 
dissolving a quantity in acetic anhydride to which some anhydrous 
sodium acetate had been added and boiling under a reflux condenser 
for two and one half hours. It was allowed to cool and was poured 
into a beaker of cold water and allowed to stand with frequent stirrings 
for ten or twelve hours. The precipitate which had formed was 
separated from the solution, dissolved in absolute alcohol and cleared 
with animal charcoal. It crystallized from the alcoholic solution in 
yellow needles. After recrystallizing three times the melting point 
was determined and found to be between 240° and 243° C. uncorrected. 
The acetyl derivatives were prepared from the yellow pigment from 
all three fungi and were apparently identical. They had the same 
appearance, solubility, and melting point. There was, however, a 
considerable difference in the yield of acetyl derivative from the dif- 
ferent pigments. The largest yield in proportion to the quantity of 
pigment used was obtained from the pigment from E. tropicalis; the 
smallest was from the yellow precipitate from E. parasitica. 
The acetyl derivative was broken down and the original pigment 
recovered by dissolving the crystals in concentrated acetic acid, with 
heat, and then adding a drop or so of concentrated sulphuric acid and 
warming again. Several volumes of water were then added and the 
pigment was precipitated out. The mixture was filtered and then 
washed with water and dissolved in alcohol. The acetyl derivatives 
of this yellow pigment from all three species of Endothia were broken 
down in the same way. The three alcoholic solutions were treated 
with a number of common reagents and reacted in exactly the same 
way in all cases. It is evident that the three species of Endothia 
produce the same pigment when grown on rice flasks and, as these 
three species are typical of the three groups mentioned earlier in this 
paper, it is highly probable that all the species of Endothia studied 
produce this pigment. This pigment will be designated pigment A 
throughout the rest of this paper. It is soluble in acetic acid, ether, 
carbon-tetrachloride, and a number of other organic solvents. It is 
slightly soluble in petroleum ether. It dissolves with a green color in 
sulphuric acid and in concentrated nitric acid. When acidified it is 
yellow and is insoluble in water. When made alkaline it has a color 
