678 Journal of Agricultural Research voi.xx, N0.9 



The identity of the long-spored, Visayan Sclerospora, then, is clearly 

 established as quite distinct from Sclerospora philippinensis. Whether 

 this distinction is sufficient to entitle the former to specific rank depends 

 somewhat upon the judgment of the investigator. The matter could 

 be settled with greater finality if the two fungi were to be grown in pure 

 culture and compared in morphological and physiological details under 

 the controlled conditions of the laboratory, but unfortunately all attempts 

 to grow the two forms artificially have been unsuccessful. In view, 

 however, of such well-defined, although somewhat relative, morphological 

 differences in the conidiophores as the peculiarities of the basal cell and 

 the branch system, and the well-marked and easily measurable differ- 

 ences in size and shape between the conidia of the two fungi, and in view 

 of the constancy and persistence of these points of dissimilarity over a 

 wide range of hosts, through several generations of maize and during 

 three months' cultivation, the writer regards the Visayan form as worthy 

 of specific distinction from S. philippinensis. The species, therefore, is 

 described as new, and as it was first found occurring spontaneously on a 

 wild host, it is named 5". spontanea. 



DIAGNOSIS 

 Sclerospora spontanea, n. sp. 



Symptoms, effect on the individual host, and destructiveness to the maize crop 

 as a whole, as previously described by the writer for Sclerospora philippinensis (12). 



Mycelial hyphae and haustoria as described for Sckrospora philippinensis; but the 

 clavate hyphae (conidiophore initials) which emerge from the stomata are longer, 

 more slender, and more irregular. 



Conidiophores as in Sclerospora philippinensis, erect, single or grouped, develop- 

 ing only at night and in dew; comprising basal cell, main axis, more or less complex 

 dichotomous branching system, and terminal sterigmata; but differing in general 

 in greater total length (350 to 550 n) and more expanded top, and in particular as fol- 

 lows: Basal cell less knobbed and expanded at the base, more slender (least diameter 

 about 5 to 8 m). and longer (140 to 260 u), usually exceeding or at least equaling in 

 length the extent of the main axis from the septum to the primary branches. Main 

 axis usually expanding more abruptly above the septum to a greater width (22 to 32 /u) 

 and constricting noticeably (to about 20 u) below the branches. Branches longer, 

 more slender, less constricted at point of origin, less recurved and ascending, but 

 standing out more stiffly. Sterigmata longer (13 u), more slender, and straighten 



Conidia resembling those of Sclerospora philippinensis in hyaline, finely granular 

 content, thin wall, rounded apex lacking papilla, and rounded base with apiculus of 

 attachment, and in invariable germination by tubes; but differing as follows: In shape, 

 longer and more slender, usually very elongately ellipsoid or cylindrical; in size, 

 showing greater length and less width, the majority being 39 to 45 /u long by 15 to 17 a 

 in diameter. 



Oospores not yet encountered on maize, although an oogonial stage on Saccharum 

 spontaneum may prove to be connected. 



Habitat. — Found in the Visayan group of the Philippine Islands principally on 

 cultivated maize (Zea mays L.), rarely on the wild grass bugang (Saccharum spon- 

 taneum L.), and once on cultivated sugar cane (Saccharum officinarum I,.). Inocu- 

 lated successfully upon the first two of these hosts and also upon teosinte (Euchlaena 

 luxurians Schrad.), and the wild grass Miscanthus japonicus (Thunb.) Anders. 

 Extremely destructive to maize, but much less so to the other hosts. 



