65 



^ 



whole plant. The hypocotyl is relatively strongly dcvel- 

 oped, swells very soon after the appearance of the first leaf, 

 and represents the first stage of the rhizome that is developed 

 later. The prhnary root is slender, rather long, and shows 

 several ramifications. It is the only root during the first stage 

 of the germination, but very often after the appearance of the 

 first leaf one or two secondary roots break out from the base of 

 the hypocotyl. Figs. 28 and 30 show two germinating plant- 

 lets, and we see in these the somewhat swollen hypocotyl 

 (C), the short-petioled, slightly curved cotyledons (Cot.), the 

 slender primary root (R), and the development of one or even 

 two secondary roots (r^ and r'^). The first normal leaf is 

 long-petioled, like those of the full-grown plant, but the blade 



4 



is entire, not palmately lobed, as is the case in the later ones. 

 The form of the young leaves is nearly kidney-shaped, the 

 margin more or less crenate and the nervation palmate ; they 

 may, however, also show an almost heart-shaped form, but 

 Ik ^ they are always palmately nerved. The first leaf next the 



cotyledons shows the principal character of the final leaf, and 

 (as appears in Fig. 30) the next one shows the same. One 

 or two leaves are then developed in the first year, and during 

 the following winter the hypocotyl increases in thickness and 

 forms a roundish tuber. It is interesting to follow the further 

 development of the young plant, and we see early the next 



r 



spring that a series of scale-like leaves precede the normal 

 ones. Fig. 34 shows such a young plant, one year old, where 



^ 



l^-H indicate four scale-like leaves, which are alternately 

 biseriate. They are very thin, almost membranaceous, cari- 

 nate and uncolored. The fifth leaf. U, is broadly heart- 

 shaped, with the margin crenate. In regard to the hypocotyl, 

 this has, as mentioned above, become still more swollen than 

 in the first year, and, while the primary root still persists, 

 some secondary roots have developed, of which r^ and 

 r- surpass it in length and thickness. These secondary roots 

 are developed at different heights from the hypocotyl, above 

 each other, and it was observed that they mostly break 

 out on the same side, in which manner the hitherto vertical 

 young rhizome is gradually forced into a horizontal direc- 



