12 
Sxor,. Il].—Tux Origin or THE DISEASE. 
It is impossible to say by what means the fungus Peronospora 
Schleideniana first reached Bermuda. There is but little doubt that 
the disease is identical with that which occurs occasionally in the 
Canary Islands, and which is known there as La Ceniza or La Escarcha, 
onion seed, or more likely on the leaves of some onion plant. On the 
other hand, microscopic examination of many specimens of onion seed, 
brought over from the islands of Teneriffe and Palma, failed to reveal 
any traces of the spores of the fungus ; and onions were raised from this 
uropean co 
woult render it difficult to obtain e suitable for the Bermuda market 
which would be entirely above suspicion. 
e thick black coat which covers the seed is too dense and hard to 
be ea a by the Tope. so that the seed cannot be directly ete 
y the fungus nor its germinating power affected. Although, in 
opinion, the danger of infection by the seed is but very slight, ri Dei in 
the section upon remedial measures suggested a method by which any 
spores existing in the seed might be destroyed without injuring the seed 
Connexion ee There seems to be some connexion between the extensive use of 
‘arti. artificial manures and the origin and spread of- fungoid diseases. The 
ficial manures potato is frequently attacked and large crops destroyed by fungus which 
d fungoi is nearly related to that causing the onion disease. The potato was 
diseases introduced into England 300 years ago, and for about 250 years it 
ourished without, as far as is known, any disease appearing among the 
cultivated varieties. But about 50 years ago, the Potato Fun ngus, 
Peronospora ripe (Phytophthora infestans, De Bary) made its 
appearance, and has never since disappeared. Its appearance was 
ifici res. A 
ight be sho 
sacle of the onion disease fungus, which did not make its appearance 
till eight or 10 years 880, and the recent extensive use of artificial 
manures in the Bermudas 
Sect. 1V.—Remepiat MEASURES. 
The question of remedial measures may be considered under three 
ig 
. What means may be taken to strengthen the onion plant, so that it 
may be better able to cea the attack of the fungus when 
it makes its appearance ? 
ii. What means may be adopted to prevent the appearance of the 
disease another year, or how can the disease be stamped 
out ? 
iii, What curative methods can be employed when the fungus has 
appeared, and what means should be ane en to prevent i its 
spreading ? 
Strengthen’ i. At present no one strain of onions is known to withstand the sn 
irre A of the sgo better than another. Any experiments carried on a 
iew of testing the relative power of resisting the disease kerti the 
