CHAPTER XI. 



RESPI RATION. 



220. One of the life processes in plants which is extremely 

 interesting, and which is exactly the same as one of the life proc- 

 esses of animals, is easily demonstrated in several ways. 



221. Simple experiment to demonstrate the evolution of 

 COj during- germination. — Where there are a number of stu- 

 dents and a number of large cylinders are not 

 at hand, take Ijottles of a pint capacity and 

 ]ilacc in the bottom some peas soaked for 12 to 

 24 hours. Cover with a glass plate which has 

 l>cen smearcil with vaseline to make a tight 

 joint with tlie mouth of the liottle. Set aside 

 in a warm pkice for 24 hours. Then slide 

 the gkiss plate a little to one side and quickly 

 ])our in a little baryta water so that it will run 

 down on the inside of the bottle. Cover the 

 liottlc again. Xote the, precipitate of barium 



' - --- carljonate whicli demonstrates the presence of 

 Fig. loi. _ ^ ^ 



Test for prosenre of C< ), in the Ixittle. Lower a lighted taper. It 



carbon dioxide in ves- ."..,,, ^ , 



sei with gurminatmg IS e-xtuiguisliei I becausc ot the great quantity 

 of <S().,.- If llower Imds are accessible, place 

 a small handful in eacli of several jars and treat the same as in 

 tlie case of the peas, ^'oung growing mushrooms are excellent 

 also for this experiment, and ser\-e to show that respiration takes 

 place in the fungi. 



no 



