EXPERIMENTS AND PRACTICAL WORK 



31 



animals feeding, e.g. horses upon guinea grass, birds 

 on oranges and guavas, caterpillars on lilies. 



Expt. 5. Useful Plants. Collect four specimens each 

 of plants made use of, as follows: 



Food e.g. cassava, yam. 



Drink e.g. coconut, cocoa. 



House-building e.g. cedar, broadleaf. 



Dyes e.g. logwood, fustic. 



Medicines e.g. Jack-in-the-bush, leaf-of-life. 



ROOTS I 



(See Tropical Readers, Book I, pp. 72-74.) 



Expt. 6. Tap-roots. Collect ten plants with tap-roots 

 (e.g. coffee, cocoa, orange, carrot, turnip, cassava, broom- 

 weed) and put those that are fleshy together. 



Expt. 7. Fibrous Roots. Collect 

 six plants with fibrous roots (e.g. guinea 

 grass, cane, corn, red lily). 



Expt. 8. Root-cap (fig. 10). Ex- 

 amine roots of the water hyacinth 

 and mangrove, and observe that the 

 root-caps at the tip are so much de- 

 veloped as to be visible to the naked 

 eye. 



Expt. 9. Growing Portion of a 

 Root is near Tip. To show that 

 only the lower portion of a root grows 

 longer, put a seedling, the root of 

 which has been marked with Indian 

 ink or tied with bands of thread at 

 intervals of about \ in. in a funnel (see fig. 11), and 

 keep moist by surrounding with damp cotton wool 

 or blotting paper. A copy should first be made on 



^ 



Fig. 10. Longitu- 

 dinal Section through 

 the Apex of a Root 



a, Axis ; r, cortex ; 

 gp, growing-point; cc, 

 root-cap. 



