Life-history of Parasitic Fungi. 
363 
The origin of Cladosporittm from Hormodendron. 
An examination of the old cultures of Hormodendron showed that the 
production of conidia of Hormode7idron had ceased. The mycelium 
remained the same, but from some of the hyphae lateral branches had been 
produced which bore pale olive conidia at their tips. These fertile hyphae 
were thicker than those which had borne conidia of Hormodendron and 
were three or four times septate. The conidia were borne in short chains 
and were typically once septate ; sometimes they were twice or thrice 
septate. They were similar in their structure and mode of origin to those 
of Cladosporinm herbartim. Some of them were seen to have germinated 
in the medium of the culture; each emitted two hyphae, as a rule, which 
were septate at somewhat short intervals and were usually unbranched. 
At the tips of the hyphae were borne short chains of conidia of Cladosporinm. 
The examination of the cultures, therefore, showed that the mycelium of 
Hormodendron after having produced conidia of Hormodendron gave rise 
to conidia of Cladosporinm , which after germination in the medium of the 
culture reproduced themselves. 
The production of Hormodendron from Cladosporium. 
The origin of Cladosporium from Hormodendron shown above led 
to a careful examination of the leaves of plants which were attacked by 
Hormodendron , for the purpose of finding out whether Cladosporium occurred 
on them. On the living leaves no Cladosporhim was observed, but the 
waning or dead leaves showed Cladosporium to be present in abundance. 
Whereas from these leaves Hormodendron had evidently disappeared, tufts 
of the conidiophores of Cladosporium could be seen growing around the 
holes previously made by Hormodendro7i as well as on other parts of the 
leaves which showed no signs of having been affected with Hormodendron . 
The dead or waning leaves of all the species which had been attacked by 
Hormodendron showed Cladosporium on them. 
Conidia of Cladosporium were taken from the leaves and were mounted 
in ‘ hanging-drops ’ in a weak solution of cane sugar. Whether they were 
continuous or once, twice, or thrice septate the conidia were found to be 
capable of germinating ; it is, therefore, interesting to note that the mature 
conidium is not necessarily septate, that is if the power of germinating is to 
be taken as the significance of maturity. Each conidium emitted usually 
two hyphae; the hyphae grew, branched, and on the lateral branches were 
borne branched chains of conidia of Hormodendron. Sometimes a hypha 
was observed to bear conidia of Hormodendron when quite short and 
unbranched. The results of the germination of conidia of Cladosporumi 
taken from different species of plants were the same; in the experiments 
conidia of Cladosporium were taken from the leaves of Cabbage, Oak, 
Catalpa , Funkia , Melon, and other plants. 
