38 MICROBES, FERMENTS, AND MOULDS. 



scribed, in the proportion of five grammes to a litre 

 of water; also a solution of sulphate of iron, one 

 kilogram to two litres of water, with which the 

 stock should be washed fifteen days before the shoots 

 begin to start (Millardet). Mme. Ponsot, in Bordelais, 

 has used the same substance mixed with lime (four 

 parts of powdered sulphate of iron to twenty parts 

 of lime). The fallen leaves which contain the 

 winter spores, or oospores, should be burnt or buried. 

 The stocks should be irrigated as often as possible, 

 and the leaves should be dusted with lime in order 

 to dry off the dew or mist, which favours the fertili- 

 zation of the oospores. 



Some species of vines resist the disease better 

 than others, and this is the case with the Labernet, 

 a vine from Me'doc, which has remained almost 

 entirely free from it in infected regions of Algeria. 



Anthracnosis, or Black-rot. This fungus, of which 

 the name is Phoma uvicola, or Sphaceloma ampelium, 

 belongs to the ascomycetes. Of all the parasites of 

 the vine it was the earliest known, but it was only 

 in 1878 that its devastations were important enough 

 to attract attention. Like the two preceding fungi, 

 it is reproduced by spores carried afar by the slightest 

 breeze. Heat and moisture are favourable to its pro- 

 pagation, which is checked by drought. 



It appears on the young shoots in the month 

 of May, in the form of round black spots which 

 gradually spread over the twigs, leaves, and grapes. 



