02 COMPANION TO TROPICAL READERS 



Expt. 74. Food Stored in Seeds. 



(a) Starch in Cotyledons. Test the cotyledons of the 

 mango, red pea, and genip for starch, by pouring on a 

 few drops of iodine solution and observing the dark- 

 purple colour produced. Compare with result obtained 

 by adding solution to pure starch. 



(b) Starch in Endosperm. Cut a grain of corn or a 

 castor-oil seed in two, and test with iodine for starch. 



(c) Manufacture of Starch. Prepare starch from mango 

 or corn seeds by grating or crushing and washing 

 with water. 



(d) Oil in Seeds. Prepare oil from coconut, castor-oil, 

 and two other kinds of seeds by grating or crushing, 

 boiling with water, and then skimming off the oil that 

 rises. 



Expt. 75. Conditions necessary for Germination. 



(a) Water for Germination. Show that moisture is 

 necessary for the germination of seeds by putting six 

 red pea seeds in a dry bottle and six in a bottle with 

 damp blotting paper at the bottom. Observe and record 

 which grow. 



(b) Air for Germination, Show that air is necessary 

 by putting corn seeds in two bottles of water. In one 

 case use ordinary water; in the other use water that 

 has been boiled and to which has been added a layer 

 of sweet oil to prevent the access of fresh air. Record 

 if there is any difference in the germination of the 

 seeds. 



(c) Warmth for Germination, Too great heat and too 

 great cold prevent germination. Put six bean seeds in 

 a tin, and heat strongly over a fire (without scorching) 

 for half an hour. Try to germinate. Put another lot 

 in a pot and keep packed in ice (if obtainable) and 

 covered with paper. 



