BROOKLYN BOTANIC GARDEN 
LEAFLETS 
Series 1 Brooklyn, N. Y., June 18, 1913 Number 9 
RESPIRATION IN PLANTS 
In the minds of most people, respiration means the same as 
“breathing”. Breathing is generally associated with the forcible 
intake and expiration of air by the lungs. Respiration should 
be thought of rather as a sort of triple process: the taking of 
oxygen to the living cells; the uniting of this oxygen with some 
of the foods or else with the living substance itself present in the 
cells; and, finally, the throwing off of carbon dioxide. While 
some details of the process are still in dispute, this view is per- 
haps the one generally held. 
Now, of course, plants do not have lungs; so that they cannot 
breathe in the sense of muscular work of lungs. But, for that 
matter, neither can many of the lower animals; for such animals, 
comprising such as the insects, worms, jelly-fish, etc., do not 
have lungs any more than plants. Insects, for example, have, 
instead, tiny tubes opening on the surface of the abdomen and 
other parts of the body, which by means of their profusely branch- 
ing system, carry air to all the internal parts of the body. Even 
the frog, as every boy knows, does most of its breathing through 
its moist skin. If its skin becomes dry through having to remain 
too long in the dry air of a school room, for example, the animal 
will die, largely through lack of oxygen. Many animals which 
live in water use gills to supply their blood with oxygen. 
Although it is true that plants do not have lungs to pump air 
into their bodies, they neverthelesss have a very efficient system 
for taking in air and for its distribution. A connected network 
of canals and air spaces goes from the leaves throughout the 
