FUNGI OF THE PACIFIC COAST. 443 



that, practically no harm is done by Feronospora viticola, 

 but that, on the contrary, the fugus is really beneficial. 

 Our native vines have a luxuriant growth of leaves; and the 

 danger is that, in our short summers, the grapes will not 

 be sufficiently exposed to the sun to ripen. But the Peron- 

 ospora arrives, with us, at a period when the vine has at- 

 tained its growth for the season; the important point being- 

 then to ripen up the grapes which are concealed by the foli- 

 age. By shrivelling up tlie leaves, the Peronospora enables 

 the sun to reach tlie grapes without loss to the vines, as is 

 shown by the fact that the vines continue to live on, year 

 after year, without apparent injury. Should the fungus be 

 introduced into Central Europe, the case might be different. 

 The foliage oi Vitis vinifera is by no means as luxuriant as 

 that of our own vines; the winters are warmer, the springs 

 earlier, and the summers much moister than here; and it is 

 quite possible that the advent of the Peronospora, by reason 

 of the greater warmth and moisture, would be some weeks 

 earlier than here, before the vine had attained its growth, 

 and at a time when the leaves are needed for the work of 

 absorption and assimilation. It might be that the intro- 

 duction of Peronospora viticola into Europe would prove a 

 repetition, on a small scale, of what has, unfortunately, 

 already happened in the case of Phylloxera." 



It will be seen that Dr. Farlow thinks that Peronospora 

 viticola is not likely to prove inj\irious in the Northern 

 States, but in California the climate and conditions are 

 similar to those of France and Italy, where he justly feared 

 its introduction. It appears with us on the wild vine at 

 the time of flowering and robs it of the leaves necessary 

 to shield the growing grapes from the scorching rays 

 of the sun. 



Sulphuring, washes, and all such remedies, used with 

 more or less success in various fungoid diseases of the vine, 

 are necessarily useless in this; for the resting spore, by 



