79 



which encloses the plumule and later forms the sheath around 

 it. The primary root (R) is the first part of the seedling 

 which becomes visible, and grows rapidly out, although not 

 attaining any considerable length. It is hairy above and 

 entirely unbranched. Fig. 96 represents the germinating 



plantlet, where the above-mentioned parts are visible besides 

 the two first leaves, the first of which alternates with the 

 cotyledon and is broadly lanceolate, three-nerved and with a 

 sheathing base. The next stage of the germination may be 

 seen in Fig. 97, which shows the appearance of a third leaf, 

 the continued growth of the root, and finally the forma- 

 tion of a very short, but distinct epicotyl between the 

 cotyledon and the first leaf. No secondary roots have 

 come out yet. A few weeks later the young leaves are fur- 

 ther developed (Fig. 98), the second and third (L^ and L^) 

 being ovate, pointed, five-nerved and with the base partly 

 sheathing. The fourth leaf (L-*) has come out, and, in regard 

 to the root system, we see that a secondary root (r^) has been 

 developed from the epicotyl, and only a little above the 

 primary one, which has attained its full size, while the other 

 one grows rapidly and has already surpassed it in length. 



In a later stage (Fig. 99) the plant has dropped the coty- 

 ledon and thereby lost its character as a germinating plantlet. 

 The primary root still persists and another secondary root 

 (r2) has been developed at the base of the first leaf (L^) and 

 opposite the first root (r^), both of which arc still unbranched. 



This is the general course of the growth of this plant, it 

 being exceedingly short-stemmed, with all the roots confined 

 to the base of the stem, which is entirely under ground. The 

 leaves gradually change their shape from ovate and sheathing 

 to fan-like and long-petioled. 



AMARYLLIDE/E. 



Agave iinivittata. 



The seed germinates in the ground and the primary root 

 is the first organ that develops. It is densely covered with 

 root-hairs, especially at its upper part, and does not show any 

 tendency to ramification for a considerable time. Fig. 100 



