August 1912.] s. ITO. AND K. SAW AD A.— A NEW EXOBASIDIUM-DTSEASE 239 



A section through the diseased spot shows the hyphae to be 

 ramifying in the tissue of the leaf and the chloroplastids des- 

 troyed. The hj-^menium is about 70-90/^ in thickness. (Fig. 2.) 

 The basidia are cylindrical clavate in shape, and usually produce 

 four sterigmata on the apex. The basidia measure 100-135,« 

 X 3-4/y. ; and the sterigmata 2-3/7. in length. Each sterigma 

 supports a basidiospore. (Fig. 3, 4.) The basidiospores are 

 oblong-obovate in shape, straight or more or less curved, h\'aline, 

 granulate and they measure 9-12/^x3-3.5/^. (Fig. 5.) Besides 

 these one-celled spores, two-celled spores are often observed on 

 the same hymenium. They are slightly larger than the former, 

 and similar in shape and color, not or slightly constricted at 

 the septum, and they are often found germinating in situ. 

 (Fig. 6, 7.) 



In the case of Exobasidium vexans, such two-celled spores 

 also have been observed; but they were recognised as "conidia" 



