24 Kingo Miyabe . — On the Life-history of 
4. There are only two stages in the development-cycle of 
Pleospora herbarnm , the ascosporous stage and the Sarcinula - 
stage. 
5. The presence of pycnidia in P. herbarum is very doubt- 
ful, and they may have entirely disappeared from its cycle of 
development. 
6 . An Alternaria - form does not belong to P. herbarum. 
7. The formation of the perithecium is purely non-sexual. 
8. No Woronin’s hyphae or similar spiral processes are 
found in the perithecia before the formation of asci and para- 
physes. The asci and paraphyses are produced from the 
same short chains of parenchymatous cells, which are formed by 
elongation and division of the pre-existing cellular group of 
parenchymatous nature filled with highly refractive contents, 
and situated generally in a central portion of the perithecium. 
In conclusion, I wish to express my thanks to Prof. W. 
G. Farlow, who has helped me throughout my work with 
valuable suggestions, and allowed me also to make a free use 
of his library and collection. 
The Cryptogamic Laboratory of Harvard University, 
Cambridge, Mass., U.S.A., July 20, 1888. 
EXPLANATION OF FIGURES IN PLATES I and II. 
Illustrating Mr. Kingo Miyabe’s paper on the Life-history of Macrosporium 
parasiticum , Thtim. 
PLATE I. 
Fig. 1. A tuft of fertile hyphae of Macrosporium parasticum, Thtim., on the 
Bermuda onion-plant, showing the manner of their protrusion through its stomata. 
a , young hypha; b, swellings at base; c, swollen basidium ; d, old basidium ; 
e, old cup-shaped one ; f, matured spore, x 400. 
Fig. 2. Optical section of a matured spore of the same, x 500. 
Fig. 3. An old fertile hypha of the same, showing a series of renewed growths 
of spore-bearing cells, x 400. 
