On the Life-history of Macrosporium parasi- 
ticum, Thiim. 
BY 
KINGO MIYABE. 
With Plates I. and II. 
JlyT ACROSPORIUM is found among a scanty list of the 
^ ^ form-genera, whose affinity to certain Ascomycetes has 
been proved with different degrees of certainty. It is to the 
labours of Tulasne, Gibelli and Griffini, Bauke, and Kohl, that 
we owe to a great extent our present knowledge of its relation 
to the genus Pleospora , and also of the rest of the phases of 
its development, conflicting and unsettled in many important 
points as these may still be. 
Early in the beginning of this year, a specimen of Macro- 
sporium parasiticum on onion-plants from Bermuda was 
kindly placed in my hands for the study of its life-history by 
Prof. W. G. Farlow, under whose directions the present work 
has been done. 
The Bermuda specimens which I have examined were so far 
advanced in decomposition that the course of the mycelium 
of the Macrosporium in its relation to the internal tissues of 
the leaves was not clearly definable. The mycelium, which was 
found in nearly every part of the leaves, sent out through 
stomata, and sometimes through the ruptured epidermis, small 
tufts of fertile hyphae. The number of the hyphae in each 
tuft varied with the size of the aperture, through which they 
protruded. In the case of the stomata, three to five seemed 
to be the common number (Fig. i). These fertile hyphae 
were simple or occasionally branched, septate and smooth. 
Their length ranged from fifty to more than a hundred micro- 
[ Annals of Botany, Vol. III. No. IX. February 1889.] 
B 
