220 GARDENING FOR PROFIT. 



This peculiarity allows it to mature quicker than varie- 

 ties that form firm heads, and gives it its great desidera- 

 tum earliness. It is the kind that is largely planted 

 in cold frames, although not so largely as the Boston 

 Market; it is also largely grown as an early open air 

 variety between the rows of the Cabbage crop. 



Black Seeded Simpson. (See figure 55.) Like the 

 Curled Simpson, this variety does not form a head proper, 

 but it differs from the preceding in being much lighter 

 colored, the leaves being creamy yellow ; it attains a size 



l?ig. 55. BLACK SEEDED SIMPSON LETTUCE. 



nearly double that of the Curled Simpson. It stands the 

 summer heat well, while it is equally suited for forcing. 

 On account of its large size, however, it might not, under 

 some circumstances, prove so profitable as a strictly 

 forcing sort, such as the Boston Market. 



Black Seeded Tennis Ball. A favorite forcing vari- 

 ety, and, as the name indicates, forming a hard head. 

 It makes few outer leaves, and for this reason can be 

 planted quite closely under glass from six to seven 

 inches apart. It is the variety so largely used in our hot- 

 beds and forcing-pits in greenhouses. 



