18 



The outermost layer is the stratum of the ripe spores already de- 

 scribed. These are not, however, the only element of which this layer 

 is composed ; for besides them there is another important element which 

 must not be overlooked : namely the spore-hearing hyphae. These 

 hyphae are hyaline, septate, little branched, about 25 jut in thickness, 

 and traverse almost vertically to the outer surface. The spores are 

 borne singly on the short projections or sterigmata, as they may be 

 called, which seem to be scattered on the hyphae without any regularity 

 (Figs. 4 and 5). The spores are sometimes so thickly borne on the 

 hyphae that the latter- are almost entirely covered by the former. 

 When the spores are removed, the hyphae show a tubercular surface under 

 a low magnification. The middle or orange-colored layer is the stratum 

 of the young spores and the hyphae similar to those in outer (Figs. 6, 7). 

 Here it is more distinctly seen that the hyphae run almost parallel in 

 a radial manner toward the outer surface. These young spores are 

 pale in color and about 3 jj. in diameter, their membrane being nearly 

 smooth or slightly uerrucose (Fig. 3, B.) The third and represents thin- 

 nest layer of pale yellowish color the still younger portion and is of 

 the same structure as the middle just discribed. 



The medulla consists of thin, hyaline hyphae forming a kind of 

 sclerotia (Fig. 8). These hyphae are septate and seldom branched. 

 Toward the outer portion they become arranged more and more in 

 parallel series, increase also in thickness and then turn to spore-bearing 

 hyphae. Thus we see that what we have designated as medulla is 

 nothing but the stroma of the fungus, from which the spore-bearing 

 hyphae spring out, and that the mode of spore-formation in this case 

 is entirely different from that in the Ustilaginece. We see further 

 that the fungus under consideration is a species of the Hyphomycetes, 

 and not of the Ustilaginece. 



We shall now try to show that it is identical with Tilletia Oryzce 

 Pat. This latter species is described by Patouillard (13 as follows: — 



" Spores globuleuses on ovoides, mesurant 3 a 5 fi de diameter, 



brunes olivatres, verrugueuses, reunies en une masse dure d'un 



noir verdatre melangees des filaments griles, incolores, a bordes 



irregulieres. 



" Attaque le fruit du riz, qui devient volumineaux, noir et dur 



comme un sclerot." 



dj Loc. cit. 



