On two species of Heterosporium particularly Heterosporium echinulatum 83 
their full size were still devoid of any partition walls. In some prepa¬ 
rations from a diseased Dianthus leaf and also from some clean cultures 
on agar, it was noticed that one end was more warty than the other 
(fig. 41). One end was studded with rather fine warts, while the other 
was quite rough with small blunt spines, placed at somewhat distant 
intervals. It was further noticed that the spores were immature, to judge 
from the fact that they were thicker at one end than at the other and 
that the thicker end was always the rougher, and further that they were 
still only one-celled. The distribution of warts could only be made out 
upon preparations which necessitated the disjunction of the spores from 
the conidiophores, i. e. in glycerine or in lacto-phenol, so that the spores 
were no longer living and their further development could not be observed. 
The living cultures in hanging drops did not permit of the use of the 
high powers of the microscope. 
The further develop¬ 
ment of the conidiophore is 
very similar to that in H. 
Betae. The first head always 
sends out a branch, which 
bears one or two spores 
together with another branch 
(fig. 42, 43). In those cases 
in which 2 spores are pro¬ 
duced on one head, one of 
the spores is nearly always 
placed upon a very short 
side branch (fig. 29 ^ and 
39). The actual prolongation 
of the first conidiophore 
was always at the level of 
the first formed spore. As 
in H. from Beta any of the 
spores may bud off another 
spore from their distal ends ™ ~ „ , , . , , , „ „ ^ . 
Photomicro C. Edge or old colony of Heterosporium 
(Ilg. ZJ, o4); DUt this was echinulatum in hanging-drop-culture on salep agar, 
not often observed, chains showing mature conidiophore (x 40). 
of not more than two spores 
were, however, seen (fig. 28, 29, 43). The process of elongation by the 
sending forth of a branch from a head of a conidiophore might be con¬ 
tinued up to 7 times, so that a mature conidiophore might consist of as 
many as 7 branches with 13—14 spores (fig. 44). The branches are never 
produced in the same straight line as the previous one, so that the old 
conidiophore denuded of its spores appeared as a much bent structure, 
each bend being at a sharply marked angle. This is well seen in the 
drawings of old conidiophores (fig. 45) and in those given by other observers. 
In the origin and development of the conidia the two Heterosporium 
are very similar to each other. The conidia are produced acropetalously, 
by a budding process from spores already-formed. The conidiophore-heads 
of H. Betae usually produce three chains of three spores each and some¬ 
times four chains can be observed, while those of H . echinulatum usually 
produce not more than two spored-chains. In the early stages of conidia 
6* 
