A Disease of Currant Canes. 



3- 



marked spores were found to have germinated in a manner similar to that 

 described for the primary conidia taken from the pink tubercles. The spores 

 first swelled to several times their former size, when germ-tubes were pushed 

 out from the sides and ends (Fig. 7). The protoplasm was granular and 

 filled with vacuoles. Septa appeared early, cutting off the tubes at their 

 points of origin. After fortA'-eight hours growth, the mycelium was found 

 to be much branched, quite dense, and not widely spreading. The main 

 hyphae had put out short branches quite simultaneously along their sides, so 

 that the lateral branches were of nearly equal length. After fifty-six hours 

 these branches were throwing off secondary conidia precisely as the mycel- 

 ium from the primary conidia had done (Figs. 6 and 7). It will be seen, 

 therefore, that the primarj^ and secondary conidia behave almost exactly 



7. Germinating secondary conidia of Tubercularia. 



alike in their germination, and in their production of fruiting bodies. This 

 is no more than might be expected when we remember that the two 

 forms are morphologically similar. 



The behavior of these colonies varied much with the food supply. In 

 plate number one, after the nutriment had become nearly exhausted on 

 account of the large number of colonies present, the mycelial threads 

 became very profusely and compactly branched, forming close colonies. 

 The protoplasm became full of very large vacuoles. In plates number two 

 and three, where the nutriment was more abundant, the threads were much 

 longer, more slender, and less branched, thus forming a more spreading 

 colony. The protoplasm was nearly homogeneous with few vacuoles. 



On March 14, 1896, colonies produced from secondary conidia were innocu- 

 lated on sterilized currant stems, neutral bean stems and acid bean stems. 

 Here again the growth was similar to that described for the primary conidia. 

 The mycelium grew slowly, but after three days, formed a thin weft over 

 the stems. After four or five days the small white cushions began to form 

 and increase in size, in nearly every respect resembling those previously 

 described. 



