176 



GERMINATION 



leaf, (p, Fig. 319.) The root is produced from the tip of the 

 caulicle, c. The caulicle is held in a sheath (formed mostly 

 from the seed-coats), and some of the roots escape through 

 the upper end of this sheath, (m, Fig. 319.) The epicotyl 

 elongates, particularly if the 

 seed is planted deep or if it is 

 kept for some time confined. 

 In Fig. 320 the epicotyl has elon- 

 gated from n to p. The true 

 plumule-leaf is at o, but other 

 leaves grow from its sheath. 

 In Fig. 321 the roots are seen 

 emerging from the two ends of 

 the caulicle-sheath, c, m; the 

 epicotyl has grown to p; the 

 first plumule-leaf is at o. 



Review. — What does a seed con- 

 tain? What do you understand by 

 the embryo? What are its parts? 

 Where is the food in the seed? What 

 are the seed-coats? What is the mi- 

 cropyle? Hilum? How may the 

 position of the micropyle be deter- 

 mined? How do seeds differ? With 

 what are these differences associated? 

 What is germination? Under what 

 conditions does a seed germinate? 

 What is meant by seed vitality? 

 What are the best conditions for 

 storage of seed? When is germination 

 complete? What is the first phenom- 

 enon of germination? Explain the relation to O and CO2. Define 

 hypocotyl. Epicotyl. Hypogeal and epigeal germination. What be- 

 comes of the plumule? Explain germination in a seed which you 

 have studied. 



Note.— Few subjects connected with the study of plant-life are so 

 useful in schoolroom demonstrations as germination. The pupil 

 should prepare the soil, plant the seeds, water them and care for the 



321. Germination is complete, p, top 

 of epicotyl; o, plumule-leaf; m, 

 roots; c, lower roots. 



