PLATE 9 1 
A-K.—Successive stages in the development of the conidia of Sclerospora spontanea 
from the tips of the sterigmata. Material found on maize (Guam White Flint). 2 to 
3 a. m. Xiooo. A-H.—The conidium enlarges gradually as more and more proto¬ 
plasm flows into it from the sterigma. I.—At the junction of the sterigma tip and 
base of the conidium a hyaline zone is differentiated. J.—In this zone a wall is 
formed across the papilla of attachment of the conidium and likewise one across the 
tip of the sterigma. K.—Both walls are bulged outward increasingly by the turgid- 
ity of the contents. 
L. —Conidium of spontanea which apparently has been broken off prematurely 
from the sterigma. Note the basal papilla. 2.30 a. m. X 1,000. 
M. —Sterigma from which the conidium has been broken off prematurely. Most 
of the sterigmata on this conidiophore still retained their conidia in situ in the condi¬ 
tion shown at J. Compare with P and Q. 2.30 a. m. X 1,000. 
N. —Conidium of 5 . spontanea which, even after germinating, still indicates by the 
character of its papilla that it was broken off. 2.30 a. m. X*>ooo. 
O. —Conidium of 5 . spontanea that in the normal fashion has been thrown off from 
the sterigma. Note the bulged out papilla of attachment. 2.30 a. m. XijOoo. 
P. —Sterigmata of S. spontanea from which the conidia recently have been thrown 
off. Note the characteristic shape of the bulged-out apices. The content has begun 
to show signs of disintegration. 2.30 a. m. X*>ooo. 
Q. —Sterigmata of 5 . spontanea. The characteristic shape of the tip is unchanged 
even in sterigmata of widely different sizes and shapes. 2.30 a. m. X 1,000. 
R. —Sterigmata of 5 . spontanea long after conidium discharge. The content is 
disintegrating and the walls have begun to collapse, a condition characteristic of 
conidiophores like that shown in Plate 10, D. 4 a. m. X 1,000. 
S. —Shriveled sterigmata with disintegrated content, such as are found on the 
dried-up conidiophore of 5 . spontanea shown in Plate 10, E. 3 p. m. X 1,000. 
T. —Conidium of 5 . philippinensis that in normal fashion has been thrown off 
from the sterigmata. Note the bulged basal papilla. Material taken from maize 
(Barbados Yellow Flint). 2.30 a. m. X 1,000. 
U. V.—Sterigmata of 5 . philip pinensis from which the conidia have been thrown 
off. Note that the characteristic shape of the bulged tip is unaltered in sterigmata 
£>f different sizes. The same material as T. 2.30 a. m. X 1,000. 
W.—Sterigmata of 5 . philip pinensis from one of which the conidium has already 
Been thrown off, while on the other the mature conidium is still retained in place. 
The same material as T. 2.30 a. m. X 1,000. 
1 The drawings were made with 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 
Qsmic acid, stained and mounted. 
