ciTEUS scab: its cause and control. 9 



Color of fungus: Light ochraceous salmon (R 15) to pallid vinaceous drab (R 45). 



Age 15 days; Growth moderate, about 1 centimeter in diameter, restricted, raised 

 about 0.5 centimeter; numerous small warts covered with pale woolly hyphse 

 irregularly penetrated and rendered dusky auricula purple near colonies. 



Color of fungus: Vinaceous buff (R 40) to pallid purple drab (R 45). 



BEEF AGAR SLANTS (FORMULA 3). 



Age 7 days: Growth moderate, about 5 millimeters in diameter, restricted, round, 



warty. 

 Color of fungus: Wood brown. 

 Age 15 days: Growth moderate, about 7 millimeters in diameter, restricted, raised; 



center warty, edges distinctly convoluted; media color unchanged. 

 Color of fungus: Clay (R 29) to ochraceous tawny (R 15). 



GLYCERIN AGAR (FORMULA 4). 



Age 7 days: Growth scant, about 1.5 millimeters in diameter, restricted, center 



raised, villous, border flattened; medium slightly penetrated. 

 Color range of media and fungus: Perilla purple (R 37) to pale purple-drab or 



pallid vinaceous drab (R 45). 

 Age 15 days: Growth poor, about 5 millimeters in diameter, restricted, raised; 



covered with dense, short woolly hyphse, border flattened, villous; medium 



moderately penetrated. 

 Color of fungus: Pallid vinaceous drab (R 45). Media close to colonies, Corinthian 



purple (R 38) to dull Indian purple (R 44). 



TOMATO AGAR (FORMULA s). 



Age 7 days: Growth moderate, about 3 millimeters in diameter, restricted, raised, 

 convolute; medium irregularly penetrated. 



Color of fungus: Ochraceous tawny (R 15) to wood brown (R 40) or pale vinaceous 

 drab (R 45). 



Age 15 days: Growth good, about 1 centimeter in diameter, restricted, raised, 

 warty, covered with dense, short woolly hyphse; medium irregularly pene- 

 trated, medium color unchanged. 



Color of fungus: Pallid vinaceous drab (R 45) to light cinnamon drab (R 46). 



MEDIA FORMULAS. 



The media used in these cultural studies were made according 

 to the following formulas, titrated to Fuller's scale, using phenolph- 

 thalein as indicator, and autoclaved at 15 pounds pressure. 



Formula 1. Molisch medium {21, p. 198) modified (acidity 7): Water, 1,000 cubic 

 centimeters; agar agar, 20 grams; cane sugar, 20 grams; peptone, 10 grams; 

 dipotassium phosphate, 25 grams; magnesium sulphate, 25 grams. 



Formula 2. Potato-dextrose agar (acidity 12): Water, 1,000 cubic centimeters; 

 white potatoes, 500 grams; dextrose, 20 grams; agar agar, 20 grams. 



Formula 3. Beef agar (acidity 10): Water, 1,000 cubic centimeters; agar agar, 20 

 grams; peptone, 10 grams; beef extract, 3 grams; sodium chlorid, 5 grams. 



Formula 4. Glycerin agar (neutral): Water, 1,000 cubic centimeters; glycerin, 

 20 cubic centimeters; agar agar, 20 grams. 



Formula 5. Tomato agar (acidity 15): Fresh ripe tomato juice, 200 cubic centi- 

 meters; water, 1,000 cubic centimeters; agar agar, 24 grams. 



