322 
When the black masses are removed irregular canker-like 
wounds, sometimes extending to the pith, are present on the 
ch, m 
continue a feeble existence until the following season, when it 
almost invariably suceumbs, owing to the formation of new disease 
spots. 
The fungus is a wound- -parasite gaining access to the living 
tissues through small wounds in the bark, broken branchlets, and 
ore especially at those points where leaf- buds or flower- -buds 
have been broken off, and as birds remove these buds rather freely, 
as in searching for insect larvæ, the opportunity for infection 
is amplo. 
Tho following account of tho life-history of the fungus is 
founded on observance of the s sequence of development and 
microscopic examination of material ohare — from artificial 
males n of previously healthy specimens. 
Whether inoculation is effected by means of spores or conidia, 
the first product is invariably a Cladosporium, which morpho- 
logically appears t o be in exact accordance with the ubiquitoti 
species, C. epip hyllum, Fries, CRT physiologically, the two 
are widely separated ; neither am I aware that any known species 
o pinde cie "hus been dido ibed capable of promoting the 
e known as gummosis, as is the case with the form under 
consideration. 
Inoculation was aoe by placing spores in a small wound 
made in the bark, or on the surface of the wound caused hy 
breaking off a barbod. Oiled silk was immediately tied round 
.the branch at the points inoculated, and allowed to remain for 
ten days, as a preventive against complications that might 
possibly have arisen from undesired inoculation by foreign, 
floating spore 
The fasci ten (i Hebe ote appeared at the points of inocu- 
lation at periods varying from sixteen to twenty days after infection 
took place, and Saten for about another fortnight, all the while 
producing spores, after which they gradually appare their 
position becoming occupied by a small drop of gum 
If a section is taken through a disease spot at this stage, it will 
be seen that the hyaline, enden septate, and much branched 
mycelium has extended to a distance of about 2mm. on all sides, 
from the point of infection, and has also Died down to the 
cambium. "Towards the centre of the diseased spot the tissue is 
completely disintegrated, the transformed material oozing to the 
surface as the drop of gum already alluded to. Towards the 
periphery of the infested portion of tissue, the slender hyphe can 
be seen in the cells, having perforated the wall, probably by 
means of a ferment secreted by the tips of the hyphæ. There is 
very little discolouration of the tissue, just a tinge of brown in 
the contents of cells recently attacked. 
Returning to the small drop of exuded gum—the increase in 
size of which may be taken as an index of the activity of the 
