SECTION 3.] 



SEEDLINGS. 



19 



28. This hypogiBom germination is exemplified on a larger scale by the 

 Oak (Pig. 36, 37) and Horse-chestnut (Fig. 38, 39) j but in these the 

 downward growth is wholly a stout tap-root. It is not the cauliole; foi 



this lengthens hardly any. Indeed, the earliest growth which carries 

 the very short oaulicle out of the shell comes from the formation of foot- 

 stalks to the cotyledons ; above these develops the strong plumule, below 

 grows the' stout root. The growth is at first entirely, for a long time 



FlQ. 31. A Beech-nut, out across. 32. Beginning germination of the Beech, 

 showing the plumule growing before the cotyledons have opened or the root has 

 scarcely formed. 33. The same, a little later, with the plumule-leaves developing, 

 and elevated on a long intemode. 



Fro. 34. Emhryo of Pea, i. a. a pea with the coats removed; the short and 

 tWok caulicle presented to view. 35. Same in advanced germination : the plumule 

 nB« developed four or five intemodes, bearing single leaves ; hut the first and sec- 

 ond leaves are mere scales, the third begins to serve aa foliage ; the next more so. 



