28 



Bulletin 125. 



July the blighted twigs often have their bark ruptured, and through the rifts 

 there is to be seen a somewhat brick-colored fungus growth. Upon ex- 

 amination with the compound microscope, this red development is found to 

 be the spore-bearing organs of a highly organized fungus belonging to the 

 genus Nedria. This genus is not an unusual one among the fungi that are 

 harmful to higher plants. . . The one upon the currant, when it seems to 

 be deeply seated and does much damage, is nearly related to the Nedria 

 ci?ifiabaria, Tode, which is common on various trees." The effects of the 

 disease in New Jersey are thus seen to be nearly identical with those ob- 

 serv'ed in Chautauqua County. 



Cultivation of the Tubercularia, 



On November i6th, 1896, another package of diseased currants was re- 

 ceived from Mr. Wilcox. The canes were badly affected, being thickly 

 studded, especially about the lower ends, with the pink cushions of Tuber- 



5. Germinating conidia of Tubercularia. Portion of tnycelium producing 



secondary conidia. 



cularia. The stems were covered and allowed to stand for a day in a moist 

 place, so that the cushions were well moistened and swollen out. In order 

 to avoid contamination as much as possible the spore-bearing tops of 

 several of these cushions, after being shaved off with a sterilized scalpel, 

 were crushed in boiled water on a flamed glass slip. Vast numbers of conidia 

 were present. Dilution cultures of these were then made in acidified potato- 

 agarin the usual manner. This was done in order that the germination of 

 the conidia, and the development of the mycelium in artificial culture media 

 might be studied. After twenty hours the spores had begun to germinate 

 freely. The various stages of germination are illustrated in Figure 6. In this 

 process the spore first swells to more than twice its original size through the 

 absorption of moisture. A small protrusion then appears at one or each 

 end of the conidium, which grows in length as a germ-tube. These tubes 

 are quite large in proportion to the size of the spore, so that as growth pro- 



