136 VEGETABLE FORCING 
High-quality seed ior greenhouse purposes may be ob- 
tained by two methods. The usual one is to purchase the 
seed from reputable dealers. If this plan is followed, it 
is important for each grower to make small plantings in 
order to determine the merits of the seed in producing a 
satisfactory crop, and in meeting definite market 
conditions. 
It is gratifying to note in this connection that a fairly 
large number of seedsmen specialize more or less in the 
development of strains of vegetables adapted to green- 
house culture. This is the ideal system and with the 
growth of the vegetable-forcing industry it will become 
more attractive to commercial seed growers. 
It is interesting to observe, however, that nearly all of 
the extensive and the most successful growers of green- 
house vegetables breed their own seed.’ This statement 
does not apply to lettuce growers, though some of them 
save their own seed, but it does to the men who are pro- 
ducing cucumbers and tomatoes under glass. These 
master growers claim that the practice enables them to 
make larger profits because of the superiority oi their 
products. 
Fig. 43.—Flat of Grand Rapids lettuce seedlings. 
When seed is saved from home-grown plants a few 
principles should be carefully observed. In the first 
place, no progress whatever will be made if fine speci- 
mens are selected from the picking baskets. It is not 
