METHODS UNDER GLASS 209 



largely excluded by the two layers of glass and the 

 usflal two accompanying layers of dirt. 



There are ten fungous diseases peculiar to the 

 cucumber. The wilt is peculiar to outdoor cucumbers. 

 This is caused by bacteria which plug up the vessels, 

 thus interfering with the water supply. This has not 

 been seen on outdoor cucumbers in Massachusetts. 



The powdery mildew is more or less common and 

 can be controlled by attention to moisture conditions 

 and light. It is seldom found on vigorous plants of 

 good texture. 



The damping fungus is troublesome to young 

 cucumbers and can be prevented by sterilizing the soil. 



The anthracnose would seem to be caused by too 

 great a difference between the day and night tempera- 

 ture. On this account it is far more common in the 

 spring in greenhouses when the fires go out. 



Besides fungous diseases there are two or three 

 troublesome pests which belong to the animal kingdom, 

 known as aphis and thrip, both of which are controlled 

 by tobacco, and nematodes, which give rise to galls on 

 the roots and can be controlled by the application of 

 heat or by thorough drying of the soil. 



Tomatoes require similar temperature and mois- 

 ture conditions to those of the cucumber. There are 

 some twelve fungous diseases recorded for tomatoes, 

 but the fruit rot and mildew are the most troublesome 

 diseases of these parts. These can be controlled by 

 spraying. They also, like the cucumbers, are subject 

 to nematodes and the same method of treatment applies 

 t . both. 



Forcing Lettuce. — The ideal soil for lettuce, 

 according to C. E. Hunn of New York, would be 

 a well-drained gravelly or sandy loam, but with care 

 in watering, a soil of heavy texture may be made to 

 produce excellent crops of the loose, open varieties. 



