XV 
THE PHYSIOLOGICAL EFFECTS OF LACK OF OXYGEN? 
I. INTRODUCTION 
More than a century ago Spallanzani published his ob- 
servations on the effect of stagnant air upon animals and 
plants. Spallanzani introduced organisms into hermetically 
sealed vessels of various sizes (which were, however, filled 
with air), and found that the smaller the vessel, the earlier 
did all life cease to exist in it. He also observed that differ- 
ent organisms show an unequal resistance to lack of air. 
As the most remarkable case he cites Anguillula aceti: 
“They live and multiply prodigiously where the volume of 
air does not exceed three inches; and die in several days 
only, when confined in a tube where the vacuum is less than 
an inch.’’? 
The further experiments on the same subject have fully 
confirmed the observations of Spallanzani. Bunge, in his 
well-known treatise on the respiration of mud-dwelling 
organisms, concludes that apparently “all transitional 
stages exist in the animal kingdom from the anaérobic 
unicellular organisms up to the most highly organized 
animals with a most energetic demand for oxygen.” * 
A series of brilliant observations have served to elucidate 
the chemical side of these phenomena. It is an established 
fact that carbon dioxide can be produced in an organism 
without the presence of oxygen. Hermann has shown that 
the excised muscle of the frog is able to do work and to 
1 Pfliigers Archiv, Vol. LXII (1895), p. 249. 
2 SPALLANZANI, Tracts of the Natural History of Animals and Vegetables. 
3 Zeitschrift fiir physiologische Chemie, Vol. XII 
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