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AMERICAN NATURALIST. 
Vol, VI.— MARCH, 1872.— No. 3 
EEEN OD 
THE BREATHING PORES OF LEAVES. 
BY PROF. T. D. BISCOR.* 
Ir the outer layer or skin be stripped from the surface of the 
green colored parts of plants and examined under a low power of 
the microscope, the stomata, or breathing pores, will appear as 
green specks in the otherwise colorless membrane. Their obj 
is to open and close communication between the eee 
Space always existing between the individual cells, and the outer 
atmosphere. 
The sausage-shaped cells constituting the essential part of the 
Organ are called the pore cells. They have the power of separa- : 
ting from each other in the middle, thus opening a free way for the 
air to the interior tissues; or in certain conditions of light and 
