142 



GROWTH OF CORMS. 



[BOOK ii. 



Such is the mode of growth of Palms, and of a great pro- 

 portion of arborescent monocotyledons. But there are other 

 monocotyledons in which this is in some measure departed 

 from. In the common Asparagus the shoots produce a num- 

 ber of lateral buds, which all develope, and influence its form, 

 as the buds of dicotyledons ; so that the cylindrical figure of 

 monocotyledons is exchanged for the conical : the internal 

 structure remains strictly endogenous. In Grasses a similar 

 conical figure prevails, and for the same reason; but they 

 have this additional peculiarity, that their stem, in conse- 

 quence of the great rapidity of its growth, is fistular, with 

 transverse partitions at its nodes. The partitions are formed 

 by the crossing of woody bundles from one side of a stem to 

 the other ; and are, perhaps, contrivances to enable the thin 

 cylinder of the stem to resist pressure from without inwards. 



In such herbaceous plants as Colchicum, the stem, after a 

 time, is a small tuber with two buds ; one at the apex, which 

 becomes the flowering stem and leaves ; the other at the base, 

 directed downwards at an obtuse angle. Such a tuber is 



'. 190, bis. 



multiplied by the latter bud, which pushes forward obliquely, 

 and turning upwards, throws up a new flowering stem in the 



