THE PALM TREE. 125 



which it -assumes, while they all partake of the same 

 general outline and character. 



It will be remember- 

 ed that in speaking of 

 the growth of trees, we 

 mentioned that the fresh 

 deposits of wood are 

 made on the external 

 surface of the trunk, im- 

 mediately under the 

 bark. This is the case 

 with all the trees, with a Endogenous wood. 



few exceptions, found in the Temperate Zone, and 

 they belong to the Exogenous plants. But the Palm 

 may be regarded as the type of the third natural order, 

 called Endogenous, which has been heretofore de- 

 scribed; and by reference to the adjoining cut, the 

 peculiar arrangement of the particles of the wood 

 may be contrasted with that of the exogenous tree. 

 In the exogenous, the centre or heart-wood is the 

 hardest ; the new growth is more spongy, while the 

 bark is quite soft. In the endogenous, the exterior 

 is hard and tough, and the interior is soft, and often 

 pithy. 



The Palms are lofty and erect trees, with slender, 

 cylindrical stems, simple or rarely forked, and are 

 marked more or less distinctly with knots or rings, 

 which show the position of leaves which have de- 

 cayed and fallen, and also indicate the progress of 

 their growth. The leaves, which are large, often 

 11* 



