that it is best to learn at once the long name the botanists 

 have given it; it is called chlorophyll. The jelly-like 

 granular substance that still lies close to the cell wall is 

 another very wonderful substance ; it is present in every 

 living part of every plant and animal ; in your own bodies 

 as well ; it is called protoplasm. 



Now put some of your water-net in a dish of water in 

 the sun. In a short time you will see little bubbles all 

 about it. If you found the net yourself, growing in a sunny 

 place, you probably noticed that there were so many 

 bubbles entangled with it that the whole mass looked like 

 green froth. It is possible to collect the bubbles that the 

 net gives off, and to find out that they are bubbles of 

 oxygen, a gas that we must have in the air we breathe, in 

 order to live at all. 



Dissolved in the water, is another gas that all living 

 things are constantly breathing out ; it is called carbonic 

 acid gas. This gas is the most important food material for 

 plants, and these little water plants are drinking it in with 

 the water all day long. Now the cells of the plants are 

 little work-shops or laboratories. The materials used are 

 water and carbonic acid. Each of these materials consists 

 of oxygen united with something else, and in every cell the 

 protoplasm, with the help of chlorophyll and sunlight, 

 breaks up this raw material, uses what it needs to make its 

 food, and gives off the oxygen that is left over into the air 

 for us and for animals generally. The food that the cell 

 manufactures is called organic matter ; it is food for animals 

 as well as for plants. The water-net uses some of it at 

 once for its own growth, but some of it is stored for future 

 use in the form of starch. In the picture of the cell, the 

 larger dots represent little stores of starch. 



When little water-nets grow up, that is, when each 

 cell becomes as large as it can be, what do you suppose 

 happens next? If there is plenty of food, the protoplasm 



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