312 



ECOLOG Y. 



monocotyledonous plants. If the seed are covered with sand, and kept in a 

 moist place, they will germinate readily. 



589. How the embryo backs out of the seed. — The embryo lies within the 

 mass of the endosperm ; the root end, near the smaller end of the seed. The 

 club-shaped cotyledon lies near the middle of the seed, surrounded firmly on 

 all sides by the endosperm. The stalk, or 

 petiole, of the cotyledon, like the lower 

 part of the petiole of the leaves, is a hollow 

 cylinder, and contains the younger leaves, 

 and the growing end of the stem or bud. 

 When germination begins, the stalk, or 

 petiole, of the cotyledon elongates. This 

 pushes the root end of the embryo out at 

 the small end of the 

 seed. The free end 

 of the embryo now 

 enlarges somewhat, 



Fig. 4<>9- Fig. 410. Fig. 411. 



Seedlings of jack-in-the- Embryos of jack-in-the-pulpit still Seedling of jacl:-in- 



pulpit, first leaf arching out attached to the endosperm in seed the-pulpit; section of 



of the petiole of the coty coats, and showing the simple first the endosperm and 



ledon. leaf. cotyledon. 



as seen in the figures, and becomes the bulb, or corm, of the baby jack. At 

 first no roots are visible, but in a short time one, two, or more roots appear on 

 the enlarged end. 



