CHENOPODIACE^ 307 



seeds and 'multiple-germ seeds have not been made. Of 

 course, the advantage of single-germ seed is in the ehmina- 

 tion, to a large extent, of "thinning." Townsend and 

 Rittue say that there is some indication that plants grown 

 from single-germ seeds produce a greater number of single 

 flowers than plants from multiple-germ seeds. It must^be 

 borne in mind that the so-called "beet seed" is in reality a 

 fruit, that a multiple-germ seed consists of several one- 

 seeded fruits, and a single-germ seed of one one-seeded 

 fruit. 



The true seed is kidney-shaped and about the size of a 

 turnip seed. The testa is thin, dark and smooth. The 

 hilum and micropyle are basal. The white and floury endo- 

 sperm Hes in the middle of the seed, surrounded peripherally 

 by the annular embryo (Fig. 117). 



Seed Production. — The beet industry in the United States 

 has been dependent almost wholly upon Germany for its 

 supply of beet seed. However, in the last year or so, con- 

 siderable activity has been manifested in the growing of beet 

 seed at home, and as a result, we are now growing success- 

 fully large quantities of seed. Since the beet is a biennial, 

 it is necessary to store the roots of the first year, and set 

 them out the following season, in order to obtain seed. The 

 "mother beets" may be tested for their sugar content before 

 planting, and only those which show the desired percentage 

 of sugar set out for seed production. The testing and 

 selection of mother plants for seed has resulted in the striking 

 improvement of beets. 



Germination, and the Seedling.^The primary root is the 

 first to appear. Soon, the cotyledons follow, pushing their 

 way above ground. The seedhng consists of a very short 

 hypocotyl which scarcely appears above ground, two rather 

 fleshy, glabrous, short-petioled, one-nerved cotyledons, and 



