192 SPRING. 



that the seed of the mustard will lose much of its 

 pungency ; and if that of the turnip be sown, it will 

 be found that many of the plants will prove to be 

 annuals, and not bulb at all. We find as many sin- 

 gular things in the modes in which the different roots 

 of themselves propagate the plant. In fleshy roots 

 that have the collet, or radical plate, at the surface, 

 such as the turnip and the carrot, there is no part 

 below that plate that will produce a leaf, or any thing 

 else than a mere filament of root ; while those that have 

 the collet on the bottom of the root, such as the onion 

 and the hyacinth, produce from gems on the collet an 

 innumerable succession of bulbs. So that in those 

 plants we have a sort of natural division between the 

 part that works in the air, and that which works in the 

 ' earth. But though there are many instances in which 

 that is the case, and where, if this collet be removed, 

 neither the part above nor the part below it would 

 continue to live, that is not a general law ; for all 

 those roots that have proper gems, or eyes, upon them, 

 as the potatoe, the dahlia, and most of the tuberous 

 and jointed roots, produce perfect plants from these, 

 and in the potatoe, the fleshy part of the tuber is 

 merely alimentary to the gem, in the same manner as 

 the cotyledones of seeds. The whole action of the 

 plant is external of the bulb or part of a bulb planted. 

 The radicle and the plumule ; the future root and the 

 future stem both proceed from the gem, are actuated by 

 it ; and the connexion with the old tuber is merely a sort 

 of umbilical cord, which shrinks and decays when- 

 ever the tubers come to maturity. The precise time 

 at which the old tuber could be removed without 



