THE 'NON-CELLULAR' TYPE 49 



produce new ones by the rapid division of 

 the cells in the region between the stalk and 

 the base of the expanded frond. 



CHAPTER V 



THE " NON-CELLULAR " TYPE OF 

 ORGANISATION 



IN the series of plants hitherto considered 

 we have been mainly concerned in tracing 

 certain lines of evolution in form and structure, 

 accompanied by a corresponding differentia- 

 tion and specialisation, amongst the cells of 

 which the bodies of the plants are constructed. 

 These culminate in such forms as the higher 

 red and brown seaweeds in which the char- 

 acter of leafy plants is very closely imitated, 

 save in one important respect. The terrestrial 

 plant, unlike the submerged seaweed, is 

 exposed to difficulties connected with the 

 water supply, and, as we shall subsequently 

 see, this has necessitated structural and other 

 developments far in advance of those ex- 

 hibited by aquatic plants. Indeed, a high 



