275 
Four plants, the result of dividing an old plant in spring, 
were also grown. These were examined on September 14th, but 
no Wart Disease was discovered. 
These results show conclusively that Wart Disease is capable 
of attacking and infecting, though to a moderate extent, both 
Solanum nigrum and S. dulcamara. It is therefore quite possible 
that when attempts are being made to eradicate the disease by 
discontinuance of potato-growing or by the cultivation only of 
immune varieties, these two plants may act as hosts for Syn- 
chytrium endobioticum. The infected area is so small and in- 
conspicuous that they may almost be said to act as “‘carriers.”’ 
In actual fact, however, they have in the past probably been of 
little practical importance in fostering the di 
Nevertheless, it should be remembered that Solanum dulcamara 
is generally distributed and common in the hedgerows in Britain 
and was noticed particularly in the hedges around the potato 
fields in infected districts in Lancashire last summer. Solanum 
nigrum, however, constitutes a greater danger; in the north it 
is rare, but in some of the Midland districts, where Wart 
Disease is widespread, it is not infrequent. 
inquiry, Mr. H. R. We ; 
infected area of Glamorganshire the weed is locally frequent. 
attempt to stamp out Wart Disease in’such spots without paying 
attention to Solanum nigrum is not likely to 
From the purely scientific side it 1s of interest to 
while certain varieties of Solanum tuberosum are immune, 
species. of Solanum, not apparently very closely related, are ee i 
ceptible. This, however, is a well-known phenomenon im the 
case of fungus diseases of plants. | 
f greater interest is the question IBS ie 
the potato plant and the possibility of Synchytrium er 
having spread from wild Solanums to the potato. Wart Disease 
was first described from Hungary, and it is by no means — 
ceivable that a minute and hitherto unknown fungus oe ts 
Synchytrium endobioticum should have passed from wild + aH 
to the cultivated either in that country or in any other where 1 
Was endemic. Vs 
The contrast between the small amount of hype rr. 
tissue found in the woody stems of Solanum nigrum and | 
of the original infection of 
f 2 | j i a 3 a ‘ id 
~ ee sre attack of the same 1n- 
vading parasite is more probably, 
itself, the result of deep-seate 
