188 



MANUAL OF MODEKN VITICULTURE. 



internodes. In some cases it starts from the peduncle and 

 travels towards the point of insertion on the cane. It 



spreads rapidly 

 over all the sur- 

 ronnding parts, arid 

 sometimes extends 

 regularly round the 

 cane, sometimes in 

 the shape of a long, 



/' \\ /n IM II \l \\1\ Wff \\"\\ narrow strip. In 



U IV, I 11 VI \\y/ II the first kse a 



thick pad of healing 

 tissue is formed 

 above the affected 

 part, the leaves be- 

 come reddish in 

 colour, fall away, 

 and the cane dries. 

 The affected tissues 

 are black at first, 

 but the blisters we 

 have mentioned 

 very soon cover the 

 black stains, which 

 become of a deep- 

 grey colour. The 

 blisters develop on 

 the surface of the 

 bark and sometimes 

 on the affected parts 



of the wood ; in this case the bark detaches in long 



strips. 



Coniothyrium diplodiella was first observed in 1878 in 

 Italy by Spegazzini ; Viala and Bavaz discovered it in 

 the I sere in 1885 ; Prillieux and Marsais found it in Vendee 

 in 1886. It extends over a considerable area in the South 

 of France in certain seasons. It was found in 1887 in the 

 departements of Aude, Herault, Gard, Vaucluse, Ardeche, 

 Drome, Isere, Rhone, Ain, and in Switzerland in the cantons 

 of Geneva and Vaud. It was found in the same year in 

 Italy and Vendee, and many departments of the south-west.. 

 Further, Viala discovered it during the course of his mission 

 in America in 1889. He found it on the boundary of the 



Fig. 154. Brown Mycelium Filaments of Dematophora 

 Necatrix (after P. Viala). 



