41 
investigated, neither had the species been correctly determined. 
The fungus has been isolated, and it is proposed to work out 
its hfe-history, whilst Mr. Brierley will investigate the Botrytis 
with which it is often accompanied. The whole question of 
the diseases due to Sclerotinia and Botrytis is urgently in need 
of thorough investigation. ; 
. Il.—Researcu. 
American Gooseberry Mildew. (Sphaerotheca mors-uvae).— 
in continuance of the work on the dehiscence of the perithecia 
and the vitality of the spores of Sphaerotheca mors-uvae, on 
which a report was drawn up last year by Mr. Cotton and Mrs, 
Alcock, a number of bushes were planted in the Experimental 
Ground, and much material was collected The mildew, how- 
ver, did not appear, and was completely absent in this neigh- 
bourhood in 1917. 
Parsnip Canker.—This research was undertaken in response 
to enquiries from the Evesham growers last January, who 
stated that hundreds of tons of roots were being lost in their 
district. The work was carried out largely at Kew, and an 
account of the disease will be found in the current number of 
the Bulletin (see p. 8). 
certain varieties is a pl of sheer good fortune which has 
d the country from a very grave situation. The matter 
should not, however, be left in this ition, as immunity 
results so far obtained have been conflicting and chiefly negative, 
and the work has had to be set aside. The problem is a large 
and important one, and a thorough investigation, along bio- 
chemical lines, is urgently needed, and should be made a whole- 
time study by a competent investigator. The small size of the 
Staff has hitherto prevented this from being undertaken at Kew, 
even were the locality suitable for the purpose. 
series of experiments, designed to show the amount of heat 
required to kill the resting spores was attempted in the yard 
attached to the laboratory, but owing to the controls becoming 
infected the results were vitiated. The yard arrears now to b 
thoroughly contaminated with wart disease spores. 
Apple Mildew (Podosphaera leucotricha).—The research on 
this disease was concluded. It was found that perithecia-forma- 
tion often took place in the older parts of the mycelium, but 
