LETTUCE. 



155 



able nitrogenous manure and responds very quickly to small 

 applications of nitrate of soda. 



Varieties. There are many varieties and each year finds 

 many additions to the list of those offered by seedsmen. In 

 the matter of quality, those forming a head like the cabbage 

 have the preference. Varieties that form only a bunch of 

 leaves are largely raised by market gardeners to supply the 

 common demand, since they are more easily grown and are 

 less liable to injury in handling than the heading varieties. 

 Some of the most desirable kinds are as follows: 



Fig 81. Head Lettuce. 



White Tennis Ball, or Boston Market. A variety 

 adapted for early spring use only. It forms a solid head of 

 medium size but quickly goes to seed in warm weather. 



Hanson. Forms large solid heads and isageneral favor- 

 ite. It is an excellent spring or summer lettuce. 



Black-Seeded Simpson. A popular forcing variety that 

 stands well without going to seed and does not form a head 

 but a mass of curled leaves. 



Grand Rapids. A very desirable lettuce for forcing, and 

 it resembles Black-Seeded Simpson. 



Black-Seeded Tennis Ball. A popular sort for forcing 

 or early garden culture. It forms a large, solid head and is 

 highly esteemed. 



Salamander. A good heading sort for summer use. 



