Violet Diseases 351 



doors tulips. It is doubtful whether it will prove a 

 serious drawback in the greenhouse. The causal fun- 

 gus causes a rotting of the bulbs, and seems also to 

 be involved in at least one form of blindness. In 

 the latter case, the fungus is found on the young bud 

 which fails to develop and finally rots off. It is very 

 probable that Sderotium tulipa Lib., S. tuliparum 

 Kleb., and 8. bulborum, all of which have been 

 found by various workers on tulips, are in reality 

 but one and the same fungus. 



The Violet {Viola Odorata) 



Cultural Considerations. With violets the form 

 of the house is not of great importance. In general, 

 however, houses devoted to violets should be con- 

 structed on the even span model. A three-quarter 

 span house furnishes too strong a sunlight. 



Violets require an abundance of fresh air. Solid 

 beds are preferred to the raised ones. In a house 

 twenty-two feet wide there should be three walks, 

 two and one-half feet wide. Each of the two outer 

 beds should be one foot and nine inches in width, 

 while each of the two inner beds should be seven 

 feet wide. 



The temperature at night should never be raised 

 higher than 45 degrees F. for the double flowered 

 varieties, and 45 to 50 degrees F. for the single flow- 

 ered varieties. The day temperature should never 

 run higher than 60 to 65 degrees F. Violets thrive 

 very poorly under high temperatures. If the mer- 



