26 



NATURE STUDY MADE EASY 



Now when the wheat or grass plant has grown for a month, and 



its leaves are large enough, cut one off, hold it to the light, and 

 examine the way those veins run. There seems to be 

 no central vein, or midrib, but all the veins run from 

 base to apex in parallel lines just like threads. These 

 are called parallel-veined leaves. All monocotyledons 

 have leaves like this : rye, wheat, barley, and all grasses 

 are monocotyledons. Nearly all plants belonging to 

 the lily class, like lilies of the valley 

 and the Easter lily, have parallel- 

 veined leaves. 



If the stem of an oak tree be cut 



across, it will show rings one for each year 



of its growth. All dicotyledons have stems 



marked in rings, and many are valuable as CROSS SECTION OF OAK, 



SHOWING ANNUAL, RINGS 



timber. 



If the stem of a palm tree be cut across, it will not show 

 rings, but a hard bark, with soft tissue inside. 

 All monocotyledons have stems like this, and 

 are of little value in building. 



You can see a cross section of any of these 

 trees at any museum, or you may pick up 

 pieces in a timber yard. It will please you and 

 interest you to notice these things, and you will 

 learn many delightful truths about the world of plants in which 

 we live, and about the wonderful ways of Nature. 



CROSS SECTION OF 

 MONOCOTYLEDON 



