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attacks caused by parasitic fungi. Unfortunately there is iti. 
to record. We find that our Board of Agriculture publishes anq 
distributes from time to time brief pamphlets dealing with sone 
of the more important diseases, while various local experimenta| 
stations carry out similar work for their own particular districts 
What little research work on the life histories of these parasites 
and the most practicable methods of keeping them within 
reasonable bounds is carried out in this country we owe to 
scientists whose time as a rule is already occupied with educa. 
tional matters. One can but hope that the future will brine 
some recognition of the nation’s losses year by year caused by 
epidemics which are frequently preventable and that this may 
lead to the setting aside of a sum of money, small in proportion 
to these annual losses, for the further study of this subject. Of 
the true economy of such a course there can I| believe be no 
doubt. 
The methods at our disposal for combating plant diseases 
may be grouped under three headings :— 
(1) Avoiding the conditions known to be favourable for 
the spreading of the disease. 
(2) Destruction of plant tissues containing the resting 
forms of the fungus. 
(3) Exterminating the parasite without injuring the host 
plant. 
(1) In many cases we have to admit that it is impossible to 
avoid the conditions which we know are favourable for infection 
and the matter is complicated by the fact that these conditions 
are not the same for all fungi. For instance the atmospheric con- 
ditions which determine whether Phytophthora infestans shall 
become epidemic or not are altogether beyond our control 
Nevertheless we can frequently choose situations for planting in 
which unfavourable conditions are not likely to occur. A classt- 
cal example of this is afforded by the history of the epidemics _ 
of larch disease Dasyscypha calycina (Schum.) Fuckl.= 
(Wilkommit) Hartig—a fungus we have already found during 
our excursions. This parasite, although occurring on larches 
in their Alpine home does little damage to them there. But 
when larches were extensively planted in the lowlands, in spite 
of the fact that judging from their vigorous growth all condi- 
tions were favourable for their culture, the fungus made rapid 
headway and became at once a pest to be seriously reckoned 
with. The explanation was given by Hartig. In the Alps the 
larch sheds its foliage and remains dormant until May, when 
the buds open rapidly and the foliage matures in the course 
of a week or two. In the lowlands, on the other hand, the buds 
begin to open far earlier—often in March—and exposed as they 
