OPJGINAL COMMUNICATIONS. 



I. — On the Vine Mildew. By Hugo Von Mohl.* 

 (Second Memoir.) 



T N bringing the subject of the Vine Mildew again before the public, 

 1 have to plead as a sufficient excuse, partly its importance, 

 and partly the circumstance that my former observations instituted 

 in September 18.5 If were restricted to the more advanced form 

 of the disease, whereas during the present year I have had an 

 opportunity of examining the malady from the first period of its 

 appearance, and, in consequence, of tracing more completely the 

 influence of the fungus upon the vine. During the last two 

 years, the disease was first observed, as well in the Tyrol as in Italy, 

 after the vines had blossomed, and the ovaries had begun to 

 swell. In the present year the malady appeared, if not sooner 

 in point of time, still at an earlier period as regards the develop- 

 ment of the vine, for in consequence of the cold wet unfavourable 

 weather the vegetation was many weeks behind that of former 

 years, so that at the time of writing this (on the 29th of June) all 

 the vines at this place are not yet out of flower. Amici wrote to rae 

 from Florence on the 8th of June, that vine branches were brought 

 to him the day before from the country, whose tendrils and un- 

 opened blossoms were infested with the fungus. The first 

 diseased vines which I met with were at Venice on the 15th of 

 June, on which day only a few scattered blossoms were expanded. 

 The vines of the Botanical Garden as well as the vineyards of 

 Murano exhibited the disease, though only to a small extent. 

 The peduncles and divisions of the blossoms, more especially, 

 were infested with the fungus, which existed, though in small 

 quantities only, on the hark at the lower end of this year's shoots, 

 and also on the leaves and tendrils. I had doubtless overlooked 



* Translated from Bolanische Zeitung, Aug. 19, 185-3. 

 t See this Journal. Vol. VII. p. 132. 

 VOL. IX. n 



