1 t l-l NC.I I'AKASITIC fl'UN Al.KYKODKS CITRI. 



shown by the infection experiments of K. \V. Uerger. (See Bulletin 88. 

 Florida Experiment Station, pp. .*>;. oS.) The fungus is extremely slow in 

 developing in the petri dishes, thus increasing the liability to contamination 

 with other fungi and bacteria. Its slow-growing habit demands therefore 

 a strictly pure culture, since the rapidly growing fungi and bacteria will 

 otherwise crowd it out completely. 



The many previous failures of the author and of others before him to 

 grow this fungus in cultures, were probably due to the fact that the petri 

 dishes were rejected too soon, or were allowed to dry out before the spores 

 had time to form mycelia and stromata. This fungus was transferred from 

 petri dish cultures to test-tubes of sweet potato (Plate I, Fig. 22), Irish 

 potato, rice, white cornmeal (Plate 1. Figs. 21, <M). and bread. On all 

 of these media, the growth was similar in general appearance to the growth 

 of Aschcrsonia flat'o-citrina. except that the color of the stroma and spore- 

 masses was red instead of yellow. The most luxuriant growth was on sweet 

 potato plugs. The characteristic red color of the fungus stroma rarely ap- 

 peared on Irish potatoes. This would seem to indicate that sugar was 

 necessary for the proper development of both the red pigment of Aschcr- 

 sonia alcyrodis. and the yellow pigment of A. flat'o-citrina. 



The growth on sweet potato plugs is given here for comparison with 

 the growth of Aschersonia flaVD-citrina on this same medium. 



1. ( )n April <s. 1JM)?, spores were transferred from cultures made on 

 January 14, 1907. The spores were streaked onto the surface of the sweet 

 potato plug with a platinum needle. On April 17, abundant growth all 

 along the streak had begun. ( )n April 2(>, a large raised red mass, 40 mm. 

 long, had formed. 



8. < )n April s. spores were transferred as in Xo. 1. On April 17, very 

 abundant growth had started, and on April 2(>, a very large red mass had 

 formed. 



.">. ( )n April s. spores were transferred as in Xo. 1. On April 17, good 

 growth with thickened points had started. ( )n April 2<>. a very large mass 

 of red growth had formed. 



I. ( >n April S. spores were transferred as in Xo. 1. On April 17. a 

 cream-colored to orange, mealy appearance was evident, spreading to each 

 side of the streak. ( )n April 2<>, an abundant growth, red in color, had 

 formed. 



KXI'KKIMKNTS IN C.KOWI.XC. AsC 1 1 KKSo\ I A AI.KYRODI S IN I.AKC.I-. <J t 'A N TIT I I-S. 



In April, r.ni;. experiments were begun in order to grow large quantities 

 of fungus for infection of Alc\rodcs citri. Ten large moist chambers, nine 

 wide-nKHlthed bottles of .V><> cc. capacity, and four petri dishes five inches 

 in diameter, wen.- prepared with sweet potato medium. The potatoes were 

 washed, peeled, washed again and put through a meat chopper. This 

 ground-up ma.ss was then washed in running water to get out tine particles. 

 and the moist medium was sterilized in the autoclave at 110 C. for about 

 20 minuu-s. After .sterili/ation. the medium appeared well cooked. 



( )n April '. these were inoculated, in the transfer closet, by spraying the 

 >urfaiv of the medium with a hand atoini/cr with a mixture of conidia in 



