60 THE TISSUES OF PLANTS 



tain portion of the cell-wall seems to undergo an increased 

 nutrition, so that it gradually forms an outward swelling or 

 protuberance ; the primordial utricle, or inner wall of the 

 lateral cellule thus formed, is inflected, as in the preceding 

 case, and a septum organizes across its cavity, by which it is 

 completely separated from the parent cellule ; after which, 

 the multiplication and further enlargement of the cells in 

 this direction takes place by the ordinary methods of 

 division. 



We have as yet no certain knowledge as to the extent to 

 which this budding process takes place in plants. It is 

 clearly the regular mode of growth among the Characece. 

 The long, tubiform, and articulated cells which form the 

 axis of these plants, give off at their points of junction 

 with each other, a circular row of buds, which ultimately 

 become elongated into a verticil of branches. It is pro- 

 bable that this process of gemmation or budding is the same, 

 in principle, as that which causes all lateral growth in plants. 

 The symmetrical arrangement of the leaves, buds and 

 branches, proves that they are subjected to definite laws 

 of development, and they must therefore necessarily origi- 

 nate in certain definite cells which have a tendency to de- 

 velope laterally, and appear to be specialized or set apart 

 from the rest for that very purpose. The process of divi- 

 sion as seen in the longitudinal development of the cells 

 of Conferva glomerata, is identical with the ordinary modes 

 of longitudinal increase in all the young and growing parts 

 of plants ; and the process of gemmation as seen in the 

 lateral development of the cells of the same plant, would 

 seem to be only a simplified expression of that same law 

 which,- in the more elaborate productions of nature, mani- 

 fests itself in the formation of the buds, branches, leaves 

 and other appendages of the vegetable axis. 



