304 BULBS AKD TUBERO US-BOOTED PLANTS. 



This form of mold is common upon many plants, 

 and at times is very destructive to root crops, as Turnip 

 and Carrot. The Onion, another bulbous plant, is often 

 attacked by the same or a similar gray mold (Botrytis). 

 The multitudes of spores borne upon the tips of the 

 branches germinate quickly, and, when lying upon the 

 surface of a Lily leaf, will bore their tubes through the 

 epidermis, as illustrated on this page. When once inside, 

 the thread increases in size, and grows rapidly in length, 

 branching and causing decay as it pushes along. After 

 the Botrytis fungus has grown for a while it may pro- 

 duce dark, hard bodies, by a peculiar twisting and knot- 



BOTRTTIS OK LILY LEAF, MAGNIFIED. 



ting of its threads. These dark masses, or sclerotia, 

 remain uninjured through the winter, and when spring 

 comes they produce peculiar trumpet-shaped outgrowths, 

 as shown on Page 306, which finally give rise to multitudes 

 of spores. These are set free, and, finding their way to 

 the young Lily, produce the destructive gray mold again. 

 These spores, by their large numbers and quick growth, 

 show how it is possible for the Lily Disease to spread 

 rapidly. The Botrytis is fond of moisture, and in a dry 

 season the Lilies may generally escape ; while, if the 

 weather is damp, the destruction may be great. Mr. 

 Kean suggests, as a remedy, "The planting of some 

 other crop in alternate rows, which, with high and 



