266 CRYPTOGAMS 



228. PROTOPLASM 



Object. To demonstrate automatic movement in plants. 

 (See also Exs. 155-161). 



Apparatus. Any twining plant of rapid growth, such as a hop 

 morning-glory, or cinnamon vine, a cardboard disk, and an upright 

 support. 



Method. Select a plant about six or eight inches high, 

 and examine it. Does it show any signs of coiling? Bring 

 it into contact with a slender upright cord or rod. Does it 

 respond ? If so, how ? When it begins to coil, note the direc- 

 tion in which it turns. Can it be made to revolve in the 

 opposite direction? 



When it reaches the top of the support, leave it and 

 watch its revolutions. 



Over the end of the stem slip a circular disk of cardboard 

 and fasten it to the support. Note the revolutions of the 

 stem and indicate the different positions on the disk. Note 

 the time of each position. Does the plant move in a defi- 

 nite period of rotation or not ? 



Does the motion increase or diminish at night? Does 

 watering produce any change in rate of rotation ? 



Protoplasm. The living substance of which plants and 

 animals are made is called protoplasm, a word which means 

 first form. It differs from all other substances in being 

 alive. Chemically it consists of varying quantities of carbon, 

 nitrogen, hydrogen, oxygen, phosphorus, sulphur, and traces 

 of several other elements, and resembles a protein. But no 

 chemist can analyze it, for in so doing it must necessarily 

 be killed, and then it is protoplasm no longer. 



The fact that it is alive gives to protoplasm several dis- 

 tinctive properties. 



