PLATE 8 1 
A. —External view of stoma ofmaize, showing knoblike outgrowths from the internal 
mycelium throughout the distended pore, io p. m. X375. 
B. —Early stages in the development of conidiophores, showing gradual elongation 
of the small knoblike outgrowths into club-shaped initials. 10 to n p. m. X375. 
C. —External view of the stoma of maize (Barbados Yellow Flint) infected with 
Sclerospore philippinensis. Arising from the stomatal pore are four partly developed 
initials while a small knoblike outgrowth is pushing up between their bases, n p. m. 
X375. 
D. —Club-shaped conidiophore initials of Sclerospora philip pinensis. Note the 
short, stocky habit and the indications that the basal cell will be short and stout. 
11 to 12 p. m. X375. 
E. —Conidiophore initials of Sclerospora spontanea at approximately the same stage 
of their development. In comparison to those of the other species (D) they are longer 
and more slender in habit, especially in the lower portion that will be cut off as the 
basal cell. 11 to 12 p. m. X375. 
F. —Conidiophore initials at a later stage than those in E, showing the buds of the 
primary branches beginning to grow out. 11 to 12 p. m. X375. 
G-O.—Conidiophores showing later stages in the development of the branch system. 
11 p. m. to 12.30 a. m. X375. 
P. —Conidiophore of Sclerospora philip pinensis at approximately the same stage of 
development as the Sclerospora spontanea conidiophore (O). Note that the basal cell 
is shorter and is cut off by a cross wall at a relatively earlier age. 12.30 a. m. X375. 
Q. —Conidiophore showing conidia budding out from the sterigmata tips. Attempt 
has been made to show the contrast between the finely granular content of the sterig¬ 
mata and the young conidia to the dense, coarse protoplasm of the main axes and 
branches. This conidiophore arose from the group of young knoblike outgrowths 
shown in Plate 7, F. 2.30 a. m. X375. 
R. S.—Later stages in the development of the conidia. 2 to 3 a. m. X375. 
1 The drawings were made w r ith the aid of a camera lucida from material which was scraped in dew from 
infected leaves at the time of maximum conidiophore production, immediately killed and fixed with osmic 
acid, stained, and mounted. The figures, with the exception of C, D, and P, show successive stages in the 
development of Sclerospora on maize (Guam White Dent) which had been inoculated with Sclerospora 
spontanea taken from Saccharum spontaneum. Figures C, D, and P are of Sclerospora philip pinensis for 
comparison. 
22330—23 - 5 
