ASCHERSONIA FLAVO-ClTRINA. 19 



stromata with spores. In forty-seven days, these separate points had grown 

 together into one waxy, yellow mass, fringed and tipped with a white 

 velvety growth of vegetative hyphae, as shown in the photograph (Plate IV, 

 Figs. 28, 29, 30). Numerous pycnidial masses were also present. On 

 Irish potato plugs, the growth of the fungus, for the first fourteen days, 

 was about the same as on sweet potato plugs. From that time on, the 

 growth was more feeble, and the yellow color rarely 

 appeared. Typical spore-masses were not so abund- 

 ant. On sterilized rice there appeared in ten days a 

 slightly yellow growth, not much raised above the 

 surface. In eighteen days, the growth had spread 

 out considerably over the surface of the rice, and the 

 color had become a decided yellow, without present- 

 ing any raised mass as described for sweet and Irish 

 potatoes. In thirty-four days, there appeared small 

 whitish patches over the surface of the yellow 

 growth. On white cornmeal, the growth of the 

 Fig. 5. fungus was the same as on rice. On bread, the 



Hyphae ofjtroma. fungus grew well and formed yellowish masses in 

 a few weeks. 



GERMINATION OF CONIDIA. 



The germination of the conidia of this fungus was very 

 slow as compared with that of many fungi. In September, 

 190(3, germination tests were made of conidia placed in 

 hanging drops of distilled water, tap water, agar, and 

 various solutions of glucose in water. These were pre- 



i 1 1 r f i Fig. 6. Conidia from 



pared by placing a number of minute drops of the solution dried pustules of 



. , . , . Aschersonia flavo- 



on each sterilized cover glass, and putting in them by atrina, x 1000. 

 means of a sterile needle a few conidia from fresh pustules of the fungus. 

 These were then placed in a moist chamber to keep them from drying out. 

 In all of these solutions some germination took place. In distilled water and 

 tap water, the germination was slow and feeble, the hyphal tube not advanc- 

 ing far. The addition of sugar appeared to increase germination up to 10 

 per cent, of sugar. Above 10 per cent, germination was retarded, and at 30 

 per cent, only a few spores were seen to germinate. In October, 1907, part 

 of the same test was repeated with the same general results ; except that in 

 this case the conidia in 5 per cent, glucose solution appeared to germinate 

 a little more readily than in 10 per cent, and the conidia in 30 per cent, solu- 

 tion refused to germinate at all. Parallel tests in part were made with 

 conidia of Aschersonia aleyrodis with similar results. 



The table below gives the result of the tests for Aschersonia flavo-citrina. 

 In germinating, the first hyphal tube usually pushed out just behind one of 

 the acute ends of the boat-shaped spore (Figs. 7, 8 and 9). The acute end, 



