LETTUCE. 251 
method is little used, however (Fig. 33, page 99). 
The character of the soil has very much to do with 
the ease of growing lettuce, and also with the quality of 
the crop. Good lettuce soils should be very open and 
porous (made so by the presence of sand and the absence 
of clay), with a capacity to hold much water, but an 
ability, nevertheless, to remain comparatively dry on top 
(page 96). 
The electric light has a marked effect in hastening the 
maturity of lettuce (pages 80, Ior). 
A lettuce crop matures in seven to ten weeks if the 
seed is sown in September. In the winter months, two 
to four weeks longer may be required (page ror). 
The first sowing (in early September) may be made in 
the open, but subsequent ones are made in flats or in 
vacant places in the beds (or possibly in hotbeds). Best 
results are obtained if the plants are transplanted twice, 
once into other flats or into temporary beds (about 4 
inches apart each way), and again into their permanent 
quarters, where they should stand about 8 inches apart 
each way (pages IoI, 102). 
Leading varieties are the Boston Market (or White- 
seeded Tennis Ball) and Grand Rapids. The former is a 
heading lettuce (Fig. 34), and the latter non-heading (Fig. 
32). There are several other good varieties (page 104). 
Aphis or green-fly is held in check by keeping the 
plants in a uniform condition of vigorous and healthy 
growth, and then by fumigating with tobacco or by strew- 
ing tobacco stems amongst the plants (page 104). 
The rot is worst in soils which remain wet on top and 
which contain much manure or decaying matter. Keep- 
ing the temperature high and the house very wet also 
favors it (page 105, Fig. 35). 
The mildew is worst in houses which are kept very 
close and warm and wet. It is most frequent when 
draughts are allowed to strike the plants. When it ap- 
pears, evaporate sulphur (first, however. improving the 
