Macrosporiu m parasiticum , Thiim . 19 
Besides these, he observed regularly on the A Iternaria- 
mycelium resting-hyphae of a very simple nature. Sometimes 
there appeared later in cultures peculiar hyphal bodies, which 
were dichotomously branched and parallel to one another. 
These bodies he considered as diseased formations caused by 
the nutrient fluids. 
In 1882 Kohl 1 started a large number of cultures to settle 
the disputed problem of pleomorphism of the plant in 
question. Briefly, he came to the following conclusions : 
(1) that in pure cultures he obtained, by sowing the asco- 
spores, only the Sarcinula- spores and the perithecia, and by 
sowing those Sarcinula- spores he obtained constantly a similar 
result ; (2) that the Alternaria-^ pores when sown always pro- 
duced the Alternaria- spores only; (3) that on the mycelium 
from the pycnospores the pycnidia and Alternaria- spores 
were formed ; and (4) that Cladosporium herb arum, Bauke’s 
Microconidium , and Epicoccum could not be found in the 
development-cycle of Pleospora herbarum. 
He adopts the view of the Italian authors in separating the 
Sarcimda- and A Iternaria -form s into two distinct species. 
Berlese, in his recent monograph of the genus Pleospora 
already referred to, places Pleospora Sarcimdae of Gibelli and 
Griffith under P. herbarum , and their P. Alternariae under 
P. infectoria , Fuckel. They are the two most common 
species of the genus, and grow on about the same host-plants. 
First, in regard to the question of the pleomorphism, the 
results of my cultures correspond exactly with those of Kohl. 
As has already been stated, . the Macrosporium- or Sarcinula- 
spores, when sown in a nutrient fluid, constantly produced 
the perithecia and the Sarcinula- spores ; and the ascospores 
from the perithecia thus obtained always reproduced similar 
perithecia and Sarcimda- spores. I have also failed to obtain 
pycnidia in any of my cultures of the ascospores. 
The accounts of the pycnidia given by Gibelli and Griffini, 
and also by Bauke, are far from being convincing. The 
1 F. G. Kohl, Ueber den Polymorphismus von Pleospora herbaru?n , Tub, in Bot. 
Centr., Bd. xviii. 1883, P- 23. 
