126 



MICRO-ORGANISMS AND FERMENTATION. 



open like skin affected by scurf; and the grapes either dry up 

 or putrefy. They are capable of imparting to wine a very 

 unpleasant srnell and taste. 



On mature grapes the fungus does not do so much harm, 

 but it is apt to check their growth. The best remedy for this 



FIG. 3(5. Peronospora viticola (after CORNU). 



dangerous parasite is sprinkling with finely powdered sulphur, 

 but this only takes effect in sunny weather. 



The second vine fungus is "false mildew," Peronospora, 

 viticola, which penetrates into the interior of leaves and fruit, 

 where it spreads and kills the cells. The conidia-carriers 

 -(Fig. 36) burst out from the stomata of the leaves in tufts. 



