I70 PLANT DISEASES 



Ascertain that the fungus is not also present on wild 

 plants in the neighbourhood of the tea plantations. 



Watt, The Pests and Blights of the Tea Plant, p. 419. 

 Massee, Kew Bulletin, 1898, p. 109, figs. 



GRAPE FLECK 



{Exobasidium vitis, Prill, and Del. 

 Aiireobasidiuni vitis, Viala and Boy.) 



Attention was first called to this disease by Dr. Viala, 

 who observed it on vines, especially Frankenthal and 

 Chasselas, in France. 



On the fruit a little dingy speck first appears. This 

 gradually increases in size, and becomes livid, afterwards 

 depressed, with the skin wrinkled and dry. The diseased 

 portion eventually becomes sprinkled with minute pale 

 golden or yellow velvety tufts consisting of the fruiting 

 portion of the fungus, w^hich originate from the copious 

 mycelium present in the tissue of the grape. This 

 mycelium is very slender, branched, white towards the 

 middle of the fruit, but becoming clear yellow just under 

 the skin. This fungus illustrates one of the most reduced 

 or primitive types of the Basidiomycetes at present known. 

 The velvety tufts on the surface of the fruit consist of 

 basidia bearing a variable number of spores — 2 to 9 — at 

 or near the apex. 



Prillieux has observed this parasite also on the leaves of 

 the vine, where it forms little white patches. 



Var. albiwi, Montem. — Dr. Montemartini has created 



