74 APPENDIX I. 
EXPERIMENT 13. TO SHOW PHOTOSYNTHESIS. 
(a) Algze or aquatic plants growing in the light. 
(1) Liberation of oxygen. 
Place a vigorous alga or other water plant, as Elodea, in a 
good light position and observe the bubbles of gas that form 
and rise to the surface of the water. By means of an inverted 
funnel over which a test-tube filled with water is placed collect 
the gas. When the tube is filled, insert into lower end a 
glowing match and observe the result. This is a test for 
oxygen. 
(2) The storage of starch. 
Examine spirogyra that has been for some time in the dark 
and test it for starch. Place the alga in the light, and after 
some hours test again for starch. What results do you obtain, 
and how do you explain them? 
(6) Leafy shoots growing in the light. 
With two small pieces of cork, by means of a pin, cover an 
area of the mesophyl of a growing leaf. Let it remain for 
about two days, and after plenty of sunlight remove the leaf 
and the cork, and kill the leaf tissues by boiling in water; 
then place the leaf in alcohol to remove the chlorophyl, after 
which place it in iodine solution, and the starch area will 
become dark. Where was there no starch storage? Why? 
A vigorous leafy shoot of a geranium may be immersed in 
water and the gas evolution observed and tested in the same 
way, and the starch storage tests carried out as for the aquatic 
plant. 
EXPERIMENT 14. TO SHOW OTHER PROTOPLASMIC 
PRODUCTS. 
(a) Chlorophyl. 
To strong or absolute alcohol in a bottle add some vigorous 
alga. Tightly cork, and in a few days observe the color of 
