716 
Journal of Agricultural Research 
Vol. XXXI, No. 8 
distribution prevailed the tissues withered only in the regions directly 
involved in the lesions. The enlargement of the latter took place 
especially toward the base and the tip of the leaf, lateral extension 
being in most instances, though not in all, checked by the veins. 
This elongation resulted in the characteristic lesions found on the 
original specimens—a striplike spot of uniform width, variegated 
with delicate, reddish-brown, elliptical or transverse zonation, and 
surrounded by a narrow reddish-brown marginal zone. The zonation, 
as expected, was found to have its origin in the intermittent extension 
of the lesion. During periods of high humidity prevailing often as 
a result of watering or the lowering of temperature during the night, 
a zone of healthy tissue immediately below and above the established 
lesion became watersoaked in appearance. With the recurrence 
of dry conditions, these portions of tissue withered and appeared as 
additional zonal increments (pi. 2, B, a to B, &). 
In contrast to the heavy infection brought about on both field 
com and sweet corn, most of the rice plants subjected to the same 
treatment showed no evidence of even incipient lesions. On two of 
the lots a sparse scattering of minute blackish specks appeared 36 
hours after being inoculated. As the rice plants were found to flour¬ 
ish in the damp chambers, better indeed than in the greenhouse, 
the pots which had yielded the incipient infections were retained in 
the chamber for 20 days. The spots, however, increased neither in 
size nor in number, and at the time the material was discarded the 
foliage was in thriving condition (pi. 2, C, a to C, d). 
The sugar cane responded to the inoculations in a manner some¬ 
what simflar to rice. Nearly all the cane plants developed minute, 
dark, rather indefinitely delimited specks on the foliage 36 hours after 
being sprayed with the suspension of conidia. As they appeared to 
suffer no ill effects from being exposed to the humid conditions of 
the damp chamber they were retained in the chamber for more than 
20 days. None of the lesions, however, evidenced any tendency 
toward further development (pi. 2, D). 
The vigorous parasitism of the fungus on maize foliage contrasts 
strongly with its failure to produce anything but incipient infection, 
in spite of especially favorable conditions for development, on the 
leaves of rice or sugar cane. That the organism would infect rice 
or sugar cane under natural conditions appears highly improbable. 
Its biological behavior is thus confirmatory of morphological evidence 
indicating its specific independence of ifelminthosporium oryzae and 
B. sacchari . 
ASCIGEROUS STAGE OF THE PARASITE 
W In discussing the specific identity of the^fungus strains developing 
on the diseased maize leaves from Florida and from the Philippines, 
mention was made of their association with entirely similar ascigerous 
fructifications. The latter develop side by side with the conidio- 
phores when diseased maize leaves are incubated in a damp chamber, 
although the minute black masses that constitute the young peri- 
thecia can not usually be discerned with the naked eye until the third 
or fourth day. Apparently the initial stages of development take place 
under the epidermis, which, however, is generally soon broken through 
and the sclerotiumlike bodies exposed to view. In its later stages 
