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which will support them, die. This is noticeable in all 

 cases of attack, whether of fungi or insects. 



The Fusisporum solani is a fungus which attacks 

 potatoes, particularly when grown in the southern and 

 midland counties of England, though it does not 

 appear to have been found in the north. It is by no 

 means a recent introduction, having been noticed sixty 

 years ago. It is frequently found growing in con- 

 junction with the Phytophthora infestans, but is easily 

 distinguished by its spindle-shaped spores. Another 

 variety Fusisporum roseolum is often noticeable on 

 decaying tubers, when it is seen in patches of rose- 

 coloured mould. Spraying does not appear to have 

 any effect on the disease, and the only recognised 

 means of keeping it in check is to select sound tubers 

 for planting, and to destroy those which are attacked. 



Macrosporium Solani. 



The fungus Macrosporium solani attacks the leaves 

 of potatoes, and, under suitable conditions, destroys the 

 plant. During the past few years it has been noticed 

 in Great Britain, on the Continent, and in America. 

 The attack is often not recognised from that of Phy- 

 tophthora infestans, but closer examination reveals 

 considerable differences. The Macrosporium solani 

 generally attacks the under side of the leaf. At first 

 a small greyish-brown spot is visible ; this extends 

 gradually, in concentric rings, and pieces of the leaf 

 eventually fall out, leaving holes with ragged margins. 

 The hyphee, which appear outside the leaf, are brown, 



