116 



FUNGI AND FUNGICIDES 



indrical, divided into numerous cells by transverse parti- 

 tions, and borne on a stout pedicel. According to Pro- 

 fessor Scribner, these spores germinate the following 

 spring by "sending out somewhat thickened tubes 

 (usually one tube issues from each cell), 

 which, after attaining a length several 

 times that of the spore, produce several 

 minute globose bodies on short and slen- 

 der stalks. These bodies, named spo- 

 ridia, are easily wafted from place to 

 place by the slightest currents of air, and 

 when they fall upon rose leaves where 

 there is moisture they send out slender 

 filaments, which probably bore their way 

 through the cuticle into the interior of 

 the leaf," where the mycelium is again 

 developed, and the disease is started for 

 another season. 



Treatment. Rose bushes should 

 be watched early in the season, and as 

 soon as any lemon-yellow spots are noticed 

 the affected portions should be removed 

 and burned. Raking up and burning at 

 the end of the season, the leaves beneath 

 any bushes that may have been affected 

 during summer, is advisable, on account 

 of the winter spores so destroyed. It is 

 well, also, to spray such bushes, and the 

 ground beneath, during winter, with a 

 solution of copper sulphate, or with some 

 other fungicide. Probably spraying with 

 the ammoniacal copper carbonate in spring, after the 

 leaves expand, would prove helpful if needed. 



A good account of this fungus, illustrated with a 

 colored plate, may be found in the United States De- 

 partment of Agriculture, Report for 1887 (pp. 369-371). 



FIG. 52. 



WINTER SPOKE. 

 MAGNIFIED. 



