Diseases of Potatoes. 
167 
number of plants produced exceptionally large leaves, reaching 
a height of nearly three feet, and failing to form any turnip 
root. A similar sport is not infrequently seen in mangels. 
No fault could be charged against the seedsman in respect of 
the seed supplied. The member has hurdled in some of the 
abnormal plants, and will keep them under observation. Some 
of the seed has been obtained with the view of experimenting 
with it at Woburn. 
Thirty-three different diseases of plants were dealt with. 
Nine inquiries were made in regard to diseased potatoes. The 
samples sent showed injuries from the following seven 
parasites : — 
1. Nectria solani R. & Bert., described in the Report of 
last year. 
2. Scab. The results of this investigation are appended to 
this Report (see page 173). 
3. The remarkable canker described and figured in the 
Report of 1902 under the name of Ciarysoplilyctis endobiotica , 
belonging to an obscure group of fungi, in which no mycelium 
was observed. It is probable that it is the same fungus 
described by Scliilberszky under that name ; but the further 
study of specimens during the year has shown that after 
separating the starch granules, and repeatedly treating the 
preparation with iodide of potassium, the mycelium became 
visible. This removes it from the Chytridiacece , and places it 
in the genus CEdomyces , as suggested by Dr. Magnus, though 
whether it is the same species as OE. leproides Trabut, which 
was found on beet in Algiers, has yet to be determined by a 
comparison of specimens. 
4. The wart disease, described in last year's Report. It 
occurs on other potatoes beside the “ Ever-good.” 
5. From Sussex were sent specimens attacked by the fungus 
Macrosporium solani Ell. et Mart. The fungus attacks the 
leaves, showing first a small brown spot, which increases in size, 
forming concentric circles as in some other fungi. Spraying 
the plants with a 2 per cent, solution of Bordeaux mixture 
would quickly kill this parasite. 
6. From Norfolk potatoes were received which had blackened 
skins, though the skin itself was intact. When the tuber was 
cut in two, the cut surface showed several brownish discoloured 
places, while the rest appeared healthy. A very strong un- 
pleasant odour was given off from the cut potato, and the 
surface became almost immediately brownish red, and afterwards 
the colour became more intense as it was longer exposed in the 
air. Under the microscope the cells of the coloured portions 
were found to be full of actively moving bacteria. Some of 
these were isolated and placed in a sterilised medium for 
