148 PLANT DISEASES 



look-out for the disease, and removing the canker-spots on 

 their first appearance, immediately dressing the wounded 

 portions with a wash of corrosive sublimate in methylated 

 spirit, or with a strong solution of sulphate of iron, and 

 afterwards painting over with tar. The fungicide and tar 

 should be applied immediately the wound is made; to 

 delay for a day or two is courting further disease. 



Wilkomm, Mikroskopische Felnde des Wa/des, vol. ii. p. 167. 

 Hartig, Unters. aiis dem Forstb. Ifist., vol. i. p. 63. 

 Hartig and Somerville, Diseases of Trees, p. 117, figs. 



VINE SCLEROTINIA 



{Sckrotmia fuckeliana, De Bary.) 



This fungous pest of the vine has two very different- 

 looking forms of fruit. One form appears as a dense, 

 velvety, olive-brown mould, exceedingly common on fading 

 and dead leaves and herbaceous stems of plants, and which 

 under certain conditions becomes a dangerous parasite. 

 This is the conidial form of reproduction, and was at one 

 time considered as an independent fungus, known as 

 Botrytis cinerea. The second or ascigerous condition 

 resembles a shallow wine-glass in miniature, not usually 

 more than one-tenth of an inch across, supported on a long, 

 slender stem, springing from a small black sclerotium, and 

 brown in colour. 



The conidial form is most injurious, and, unlike most 

 parasites, attacks numerous plants belonging to widely 

 separated families. It is especially destructive to vines, 

 destroying the leaves, young shoots, and also the in- 

 florescence and fruit. 



