Macrosporium parasiticum, Thiim. 9 
budding of a yeast-plant. The spore, when it was ripe, could 
not be distinguished from the older one by its side (Fig. 6 ). 
This 'budding’ process may be more common than I am 
aware in the spore-formation of this plant. I have observed 
several instances which strongly suggested this process ; but, 
as I did not observe their earliest stages, I cannot state here 
positively its occurrence beyond the case just described. 
Concerning the further development of the perithecia, it 
will be convenient to take a plant about a week old and 
follow its development. The mycelium was then blackish in 
colour, and full of young perithecia and Macrosporium - spores 
in different stages. The oldest perithecia were abou,t 0.3 mm. 
in diameter. They were generally globular in shape. Their 
internal structure was still undifferentiated, being composed 
of cells of similar shape and size, and equally filled with 
glycogen and fatty matters. 
The growth and division of the cells continued to take 
place in all parts of the perithecium. The cells towards the 
outside began to grow more rapidly in size than those in the 
central part, where the cells remained almost at their original 
size, as they multiplied by constant growth and division. 
A large number of the cells in the central portion then 
became markedly filled with very refractive contents. Their 
number and position in the perithecium were variable, and 
could not be stated definitely. As to the position, sometimes 
they were found in the upper portion, sometimes in the lower, 
but commonly near the centre of the perithecium. These 
cells soon began to elongate and divide mostly in an upward 
direction, forming a body of short irregular chains of cells, 
which might be either simple or branching (Figs. 10 d and 1 1 b). 
From the tip of each of these chains of cells, one, two, or 
rarely three slender hyphal branches were sent out (Fig. 11, 
A, C). The branches or paraphyses thus formed in large 
number, at first crossed each other to a greater or less extent. 
They, however, soon took a definite upward course in a closely 
packed bundle towards air and light. The larger part of the 
parenchymatous cells lying above in the way of these rapidly- 
