PLATE XV 
Fig. A .—Hypomyces ipomoeae (Hals.) Wollenw.: Sweet-potato strain, its perithe- 
cial stage isolated in 1907 by Dr. Donald Reddick, Cornell University Experiment 
Station. (See legend of PI. XIII.) 1,2, Grown in pure culture on cotton stem; 3, on 
maple stem; 4, on wheat straw; 5 and 6, on potato cylinder. X50. 
Fig. B-C .—Hypomyces caneri (Rutg.), n. comb.: The hemp strain found with peri- 
thecia on a dead taproot of hemp at the soil level, Potomac Flats, Washington, D. C., 
1912. The perithecia and ascospores are larger, but the conidia are less septate than 
those of the sweet potato strain. B, Grown on steamed com kernels. C, 1, Perithecia 
from the original field material; C, 2, 3, Grown in pure culture on cotton stem. X50. 
Fig. D-G .—Gibberella Saubinetii (Mont.) Sacc.: The mycelium stage was isolated 
in 1912 from sweet-potato tubers by Mr. C. A. Ludwig, Lafayette, Ind. The writer 
obtained perithecia after the second transfer of conidia on cotton stem, wheat straw 
and heads, potato stem, etc. The first perithecia appeared gregarious on a coremium- 
like or irregular plectenchymatic stroma. D, Grown on stem of Robinia, which was 
more or less reduced when single ascospores of these perithecia were transferred to 
fresh moist steamed stems of plants; F and G, grown on cotton stem (on almost dry 
wheat straw the stroma could be reduced still more and completely disappeared in 
Some of the later cultures on this medium); E, grown on wheat straw. 
