NATURE STUDY MADE EASY 



67 



in Canada. There, most of the trees are exogens, and yield very 

 slowly to the saw. The bark is the softest, and the cutting gets 

 harder as one nears the heartwood. These men were later em- 

 ployed to cut timber in the West Indies. Here most of the trees 

 are endogens, and the bark wood is hard, while the interior is soft 

 and easy to cut. But these workmen knew nothing of this. Accord- 

 ingly they started at their work. They worked 

 hard for an hour without any success. , 'I give 

 it up/ said the first; 'there's no cutting through 

 this.' 



'Right/ said his comrade; 'if this is the 



outside, what must the inside be? I give it up, 



too.' If they had only known as much as 



Tom Brown, they might have finished their task. 



" Bamboo and sugar cane have no bark. 



CROSS AND LONGITU- 

 DINAL SECTION OP 

 MONOCOTYLEDON 



STEM 



Their hardest 



wood is on the outside. They are only giant grasses." 



LANGUAGE LESSON 



Draw a cross section of an exogen six years old. 

 Draw a cross section of an endogen six years old. 

 What is the heartwood ? Which trees are most valuable for build- 

 ing? Why? 



