BY D. McALPIKE. 
445 
The above table shows that it is not a mere matter of moisture 
which settles the greater or less prevalence of the disease, but 
other conditions, such as accompanying heat or cold, will also 
influence it. 
Generally the spores are plentifully produced about the 
beginning of the year, and the leaves have usually all dropped off 
by April. It is very noticeable how the leaves fall away from 
the lower ends of the branches, leaving only a small tuft of leaves 
at the top, which may be regarded as the expiring effort of nature 
to renew the foliage of which the tree is prematurely deprived. 
Hosts and Parts Attacked. 
I have found the fungus in Victoria on the leaves of the peach 
and its smooth-skinned variety the nectarine, the plum, the 
apricot and the almond. It is most prevalent on the plum and 
peach and comparatively rare as yet on the apricot and almond. 
In other parts of the world the disease is found on other species 
of Prunus. In California it attacks the cherry in addition to the 
above, and in the old world it is found on the sloe or blackthorn 
( I'runus spinosa j and other species. Although this fungus has 
only been known elsewhere to attack the leaves, I had a specimen 
sent from Wangaratta in which the fruit was affected. It was 
very noticeable that only one side was attacked, and presented 
the appearance of a number of pimples or blisters of a brownish 
colour. The fungus was evidently not so far advanced as on the 
leaves, so that the conspicuous rusty colour was not so apparent. 
In South Australia the disease has been found on the peach, 
plum, apricot and almond leaves, as well as on the fruit of the 
apricot. The latter specimen was kindly sent to me by J. G. O. 
Tepper, F.L.S., for determination, and he was naturally surprised 
to find the leaf-rust become a fruit-rust. It is rather peculiar 
that no previous record of such a comparatively common rust 
should be known on fruit outside of the Australian colonies, but 
it only shows what a glorious climate we have for luxuriant 
growth, that of fungi included, and it points to the grave danger 
of allowing fungus pests to run rampant, for they may attack 
