268 



STATE BOARD OF AGRICULTURE. 



surface of the wort, in the case of the lioating growth, becomes slightly 

 yellowish, the part in the air remaining snow-white, and radiating in 

 fine threads from the centers of growth. In six days the top of the 

 wort becomes nearly covered. The growth extends in small radiate, al- 

 most transparent growths, about one-fourth of an inch in diameter 

 upon the walls of the tube for a distance of three-fourths of an inch 

 above the surface of the wort. In ten days the mycelium becomes 

 felted and yellowish in color. 



On Potato — Cultures on potato, in test-tubes become nearly covered 

 with a felted growth in about seven days. The mycelium, where it 

 comes in contact with the liquid, is white and cream-colorod. There is 

 no color on the potato when grown in this way. The surface exposed 



^V^ 



Fig. 18.- -Development of spores of Lecanium disease: a, gonidia germinating, after 18 hours in agar; 

 b, after 24 houre; ^, still later; d, aerial threads with sterigmata and gonidia; <>, hyphal bodies, 

 some germinating, enlarged, original. 



to the air is quite yellow in color. Filaments grow up the sides of the 

 tube, making a narrow border. When grown in larger quantities in 

 Ehrmeyer flasks, it produces elevated, yellowish felted masses in 

 places, with a thin, transparent, white growth all over the potato. Af- 

 ter about twelve days, the potato is tinged with a slight purple near the 

 more dense growths. The points where the inoculation took place are 

 covered with elevated masses of felt. After about a -month, one flask 

 showed a number of differentiated points of growth, small and ele- 

 vated, appearing like small white shot laid on the surface of the 

 growth. These may have been the result of an attempt to produce a 

 perfect stage. No structure could be made out on microscopic exami- 

 nation. 



On Corn Meal — On corn meal and wort the growth is slow. It is 

 white at first but later it turns yellowish in places. The growth 

 spreads from small elevated centers. 



