CONSTITUENTS OF THE PLANT. 165 



and phanerogams, but is found in the vegetative parts. It is seen in 

 the mycelium of Fungi; in the Euphorhias among phanerogams it is 

 especially manifest. One of these — E. phosphorea — gets its specific 

 name from this quality. The plant grows luxuriantly in the jungles of 

 Brazil. "Wild animals, hunted at night, break down the plants in 

 their flight; the phosphorescent milky juice clings to their hides, 

 which seem to drip streams of fire, giving the most weird character to 

 the scene. The Sunflower Family is highly phosphorescent, notably 

 the French and African Marigolds. So are the Evening Primroses, 

 the Nasturtions (Tropaeolums), and the Poppies. In all these, how- 

 ever, the glow is confined to the fiowers, emitting mimic flashes or 

 surrounding them with a soft halo. It is seen in its greatest brilliancy 

 between sunset and midnight. 



406. Organic Constituents. Cellulose. — In burning a 

 plant we see 90 to 99 per cent, of its substance disappear, 

 being reconverted into water (vapor) and air, out of which 

 the embiyo drew its first pabulum. We remember that 

 the vegetal cell consists of cellulose and protoplasm (37), 

 and that cellulose consists of water and carbon. Water is 

 composed of Hydrogen and Oxygen ; so that cellulose has 

 three constituents,— Carbon, Hydrogen, and Oxygen; it is 

 therefore called a ternary compound. 



It gets its hydrogen and oxygen chiefly from the moisture which is 

 absorbed by the roots, and these two elements are in the same propor- 

 tion in cellulose as in water. The roots also absorb a little carbon, 

 which exists in the water. The greater part of the carbon, however, 

 is provided by the leaves, which inhale it in the air they breathe. 

 It is in the form of carbonic acid gas (carbonic anhydride) both in 

 water and in air. Hydrogen, oxygen, and carbon are inorganic ; 

 but the protoplasm in the leaf and in the green bark, aided by sun- 

 light ancf chlorophyl, combines them, digests them, and converts them 

 into the starch of wheat, the flesh of fruits, sugars, gums, resins, 

 oils, etc. 



407. Protoplasm (sometimes called Proteine, from Pro- 

 teus, on account of its many changes of form). — Sugar and 

 starch, though good as food, will not make animal flesh or 

 muscle ; and animals (which use organic food alone) must 

 get the elements of flesh from the plant also. Nature pro- 

 vides for this need. Air consists of Oxygen and Niti-ogen. 

 In every thunder-storm the Electricity combines some of 

 this nitrogen with the hydrogen in vapor or water, making 

 Ammonia, which is also given out by decaying vegetal and 

 animal matter. Ammonia is readily soluble in water ; the 

 rain washes it into the earth ; young roots eagerly absorb 



