LESSON 0.] SLUTKURANKAN FORMS: TUBKRS. 



43 



Trillium or Biithroot (Fig. <)7) life is rcdiiccil to a very narrow 

 spun, only an inch or less intervening between death beneath unJ 

 young life in the strong l)U(l aniuially renewed at the summit. 



lO.J. A Tuber is a thiekiMied portion of a rootstock. When slender 

 subterranean branches, like those of the Quick-grass or Mint (Fig. 

 G4), become enlarged at the growing end by the accumulation there 

 of an abundance of solid nourishing matter, tubers are produced, like 

 those of the Nut-gnt-*s of the Southern States (which Jiccordingly be- 

 comes a greater pest even than the Quick-grass), and of the Jerusalem 

 Artichoke, and the Potato. The whole formation may be seen at a 

 glance in Figure G8, which represents the subterranean growth of a 

 Potato-plant, and shows -the tubers in all their stages, fmm shoots 

 just beginning to enlarge .it the tip, up to fully-formed |K»tatoes. 

 And Fig. GO, — one of the forming tubers moderately magnilied, — 

 plainly shows the leaves of this thickening shoot, in the form of little 

 scales. It is under these scales that the eyes appear (Fig. 70) : 

 and these are evidently axillary buds (43). 



lot. Let us glance for a moment at the economy or nio<le of life 

 of the Potato-plant, and similar vegetables, Jis shown in the mor- 



FIC r». Fiirniinc tiiliors of tlir I'lilnlo. Ctl. Our iif llip vor> yoiinp (xJarn 

 magnified. 70. Slice <>f a iMiriion (lirmigli an t-yo, iiiiiro iiinifiiilivd. 



