EXPERIMENTS AND PRACTICAL WORK 



53 



Expt. 76. Development of Seedlings (figs. 23, 24). 

 (a) Changes that take 



Plumule 



2)lace as Embryo grows. 

 Plant about twelve bean or 

 corn seeds, and by taking 

 them up at intervals of two 

 days observe the changes 

 that take place. Make 

 drawings of about six 

 different stages, showing 

 how the radicle and 

 plumule develop. 



(b) Position of Seed-coats. 

 Grow seedlings of any 

 six kinds of plants (e.g. coty- 

 cocoa, coffee, corn, red pea), 

 and record in which cases 

 the seed-coats remain be- 

 low ground and in which 

 they are brought above it. 



(c) Modified Cotyledons. 

 Examine seedlings of 

 the red pea and observe 



that the lowest pair of leaves (in reality the cotyledons) 

 differ from the real leaves higher up. 



ledons 



..article 



Fig. 23. Germinating Bean 



HOW A PLANT FEEDS I and II 



(See Tropical Headers, Book II, pp. 68-74.) 



Expt. 77. Roots absorb Mineral Matter in Solution 

 from the Soil. 



(a) Soluble Matter in the Soil. Shake up a handful of 

 soil repeatedly in a bottle with about twice its own 

 volume of water; filter and evaporate the filtrate. The 



