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After forty-two hours there was no further change, except in the increased length of the — 
germ tubes and the increased number of spores with two and three septations. At no time 
was any suggestion of a change of colour observable in the conidia. 
The ascus stage was not found in culture, but, as stated elsewhere, its connection 
with the conidial stage has been traced. 
Inoculation Experiments. 
Several seedling Avocados in the greenhouse were inoculated with conidia from cultures 
on oatmeal agar and with pieces of mycelium. In each case a small incision was made in 
the bark, the infective material inserted, and the branch at the point of inoculation was 
kept moist for about forty-eight hours. 
Fie. 5. 
Conidia after 24 hours at 25° C, 
The plants which were inoculated with conidia soon showed signs of infection. The 
tissues around the incision became discoloured and sunken; in some cases the affected 
area slowly increased in size for a few weeks until it was about 1 cm. in diameter, and then 
its progress was arrested. Two trees became completely girdled, the whole stem was 
invaded and killed, and after six months typical conidia were produced. The pycnidia 
and conidia on these artificially infected trees were identical with those found on twigs 
in the orchard. 
PATAOLOGICAL HISTOLOGY. 
The fungus appears to be a wound parasite. In the cortical tissues of infected twigs — 
there is a rather coarse brownish mycelium about 3:5 «thick. The cell walls are discoloure 
but there is no very prominent deposit in any of the cells. At certain spots there are m 
of densely woven hyphae in the epidermal and hypodermal cells, which rupture the « 
