THE NUTRITION OF PLANTS 



155 



upon respiration, which means the absorption of oxygen by 

 the protoplasm, the breaking down of protoplasm, and the 

 giving off of carbon dioxide and water as wastes. The im- 



FiG. 146. The common Northern pitcher plant. The hollow leaves, each with a hood 

 and a wing, form a rosette, from the center of which arise the flower stalks.— 

 After Kerner. 



portance of this process may be realized when it is remem- 

 bered that there is the same need in our own living, as it 

 is essential for us also to '' breathe in '' oxygen, and as a 

 result we '^ breathe ouf carbon dioxide and water. This 

 breaking down or ''oxidizing'' of protoplasm releases the 



