30 



THE VEGETATIVE ORGANS 



overshadowing plants. These clinging organs are known 

 as tendrils, and are of great use to plants with stems too 

 long and too slender to support themselves in an erect 

 position. In some plants, however, tendrils are formed 

 from organs other than leaflets. 



a.r 



Fig. 12. Grains of Wheat and Maize. i, grooved surface ; 

 2, convex surface of Wheat grain ; 3, 4, and 5, stages in germina- 

 tion of Wheat grains; 6, germinating grain of Maize ; a.r, adven- 

 titious roots ; em, embryo ; /, foliage-leaves ; PI, plumule ; ra, 

 radicle ; r.c, root-collar ; r.h, root-hair ; sh, colourless sheath. 



(b) Monocotyledons 



The Wheat grain. Embryo with one cotyledon ; the endo- 

 sperm. Soak a few grains of Wheat in water for a day ; 

 then place some of them in a jar lined with wet blotting- 



