ENDOGENOUS STRUCTURE. 



129 



SECT. VI. THE ENDOGENOUS OR MONOCOTYLEDONOUS STEM. 



220. A cursory notice must now be taken of the stem of Endo- 

 gens (or Inside- growers), a, great class of plants, which, although 

 they have many humble representatives in northern climes, yet 

 only attain their full 



characteristic devel- 

 opment, and display 

 their noble arbores- 

 cent forms, under a 

 tropical sun. Yet 

 Palms the type of 

 the class do ex- 

 tend as far north in 

 this country as the 

 coast of North Caro- 

 lina (the natural lim- 

 it of the Palmetto, 

 Fig. 166); while in 

 Europe the Date and 

 the Chamserops have 

 found their way to 

 the warmer parts of 

 the European shore 

 of the Mediterrane- 

 an. The 

 manner of 

 their growth 

 gives them 

 a striking 

 appearance; 

 their trunks 



being unbranched cylindrical columns, rising majestically to the 

 height of from thirty to one hundred and fifty feet, and crowned at 

 the summit with an ample plume of peculiar foliage. Their inter- 

 nal structure is equally different from that of ordinary wood. 



221. The stem of an Endogen, as already remarked (185), 

 offers no manifest distinction into bark, pith, and wood ; and the 

 latter is not composed of concentric rings or layers, nor traversed 



FIG. 166. The Chamaerops Palmetto, in various stages, and the Yucca Draconis. 



