SEED-BEARING PLANTS 443 
when the seed germinates. 1 At the same time the integu- 
ments of the ovule develop into a hard, horny seed-coat. 
This kind of seed-coat is characteristic of the Liliaceae. 
395. Germination of the Seed. The seeds are mature 
by about June, and lie on the ground dormant until the 
following April, when they germinate. Both ends of the 
embryo elongate, absorbing all the endosperm for nourish- 
ment. By about the time that older plants are blossom- 
ing, the young seedling has reached the stage shown in 
Fig. 322,2. At one side, near the end of the hypocotyl, 
there develops a root, and the tip becomes enlarged into 
a bulb by the storage of starch, manufactured by the 
green, cylindrical seed-leaf. Within this bulb the first 
bud (plumule) develops, the seed-leaf withers, and the 
young seedling remains in this condition during the 
following winter. 
396. Formation of Flower Bulb. In the spring of the 
second year several runners develop from the first-formed 
or plumule-bulb, and at their tips bulbs also form, called 
runner-bulbs. From each of the runner-bulbs, three more 
runners, with bulbs, are produced, and one of these bulbs, 
under favorable conditions, produces a flowering plant. 
It takes at least four years to produce a bulb that will 
develop a flowering plant. 
"The following table illustrates the number of plants 
of different ages during each of five years, supposing that 
five seeds from each fruit ripen and survive the cycle, and 
provided that all fourth year bulbs produce flowers." 2 
1 It will be instructive for the class to discuss the origin and mode of 
formation of the starch in the endosperm. 
1 Quotation and table from Frederick H. Blodgett, Bull. Torrey Club 
27 : 3 7-3o8. 1000. 
