AMERICAN JOURNAL OF SCIENCE. 
[THIRD SERIES.] 
+o 
ART. XLIX.— Respiration of Plants; by W. P. WILSON, S.D. 
THE process of breathing in animals and plants is essentially 
the same. In both the free oxygen from the air, or surround- 
ing medium, is carried into the living tissues, where, after a 
series of chemical changes, carbonic acid, water and perhaps 
some minor compounds are evolved as excretory pacducts 
e changes in the nyAng cell, alike in animals and plants, 
determine the amount of oxygen taken up and the products 
given off. on both an ares of temperature is a direct effect 
animal- or race be deprived of oxygen for any considerable 
length of time the life activities cease, and, later, death ensues 
This oxygen-respiration is then a constant need of the living 
cell, whether it be of plant or animal. 
When plants possessing chlorophyll are exposed to the sun- 
light they carry on a process of assimilation, in which organic — 
substance is produced from carbonic acid and water, and oxy- 
gen set free. The amount of carbonic acid decomposed and ve 
n given off, in this preparation of organic food for t 
plant, far exceeds, as a rule, the carbonic aed raat and ra 
ossEen taken up in respiration. Thus it happens that the 
process of respiration, in plants containing chlorophyll and 
exposed to the light, is a hidden one, and difficult of demon- 
stration 
Am, JOUR. Scare Serres, VOL. XXIII, No. 138.—June, 1882. 
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