THE SEED 



Fie. ii. 

 Squash seed 



seeds is the coconut. The Big Trees of California have 

 seeds so small that 500,000 of them weigh only one kilo- 

 gram ; but a tree grown from one of these seeds may 

 weigh a thousand tons. 



Study of Squash Seed. Examine a squash seed, noting its shape. Draw 

 the seed. In the sharper end is a small hole, the micropyle. Carefully 

 remove the testa, or outer coat. The thin, greenish inner 

 coat, the tegmen, may then be seen. Remove the teg- 

 men ; what is left is the embryo. Its sharper end is the 

 radicle. Two fleshy cotyledons make up the most of the 

 embryo ; they are attached to the up- 

 per end of the radicle. Between the cotyledons, at 

 the base, is a small, triangular structure, growing 

 on the top of the radicle ; this is the plumule. 



Germinate squash seeds on moist paper, or in 

 sand or sawdust. What part is first to come out of 

 the seed? Where does it come out? In what di- 

 rection does it grow? Plant some of the seeds in 

 sand, sawdust, or earth. What parts appear first 

 above the surface? Try to germinate 

 seeds under water; what happens? 

 Let the sand in which some are germi- 

 nating become dry ; what happens? 

 Study of the Bean. Study a bean in the same way. 

 Are the seed coats separable? Is the embryo straight? 

 Do the cotyledons of all seeds appear above the ground? 

 Study of Coconut Seed. Remove the husk and hard 

 shell of the coconut ; what remains is the seed. The seed 

 coats are thin and inconspicuous. The meat of the coco- 

 nut, which, when dried, is copra, is a part of the en- 

 dosperm ; the water inside the meat is also a part of the endosperm. 

 Embedded in the meat, under one of the three eyes, is the embryo. 

 Split it. The end next the shell is the radicle. The other end is the 



FlG. 12. Germinating 

 squash seed 



Kic. 13. Gcr- 

 minaiintrlHMn 



