88 PARASITES BELONGING TO THE GENUS GLOMERELLA. 



ORANGE TO RUBBER PLANT. 



On February 4 two leaves of a small plant in the laboratory were 

 inoculated by making a slight incision across the midrib near the tip 

 and immersing the leaves in sterile water containing conidia from a 

 culture. After five weeks no signs of infection were apparent. The 

 leaf was removed from the plant, its surface thoroughly washed with 

 corrosive-sublimate solution, and placed in a moist chamber. Twelve 

 days afterwards, the leaf showed abundant acervuli extending about 

 3 inches from the tip. The two checks treated in the same manner 

 throughout produced no Gloeosporium when kept in a moist chamber. 



ORANGE TO TEA. 



On February 4 two leaves of a growing plant in the laboratory were 

 inoculated by making a slight incision in the midrib and immersing 

 the leaf in sterile water containing conidia. A check was also treated 

 in the same manner but not inoculated. The inoculated leaf devel- 

 oped immature acervuli on a small dead area surrounding the punc- 

 ture while still attached to the plant. The check leaf was removed 

 and placed in a moist chamber, but no Gloeosporium developed. 

 Another leaf, however, on the same plant which appeared healthy was 

 removed and placed in a moist chamber and this developed abundant 

 acervuli, which indicates that it is practically impossible to determine 

 whether or not a leaf or any portion of a plant already contains the 

 fungus in a dormant condition. Results of experiments of this kind 

 are thus shown to be somewhat uncertain. 



PEPPERWORT TO COTTON. 



Stigmas of two cotton flowers from the greenhouse were inoculated 

 by the application of conidia in sterile water. The young bolls soon 

 dropped off. They were kept in a moist chamber but no Gloeospor- 

 ium developed. 



PHORMIUM TO CABBAGE. 



Five young plants in pots in the laboratory were sprayed with dis- 

 tilled water containing conidia and then covered with a bell jar. 

 Leaves of both inoculated plants and checks soon turned yellow and 

 dropped off. All these leaves were placed in moist chambers. Acer- 

 vuli of Gloeosporium appeared on the inoculated leaves but not on the 

 check. In two cases acervuli were produced on the inoculated leaves 

 while still attached to the plant. 



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