BREATHING IN ANIMALS 



stored up by the Ether in the living plants that the 

 animal had consumed. To us, who move about on 

 the floor of an aerial ocean, drawing therefrom the 

 breath of life, but which our immersion in the water 

 near us would quickly end, it seems at first thought 

 strange that the respiration, on which all animal life 

 depends, should be identically the same to the inhabit- 

 ants of the water as to those of the land, the former 

 breathing through the gills the oxygen dissolved in 

 the water, the latter, through the lungs, that in the 

 air. The water contains only four per cent, of its 

 volume of free oxygen and the air twenty per cent.; 

 yet as the contact of the fluid with the blood, through 

 the gills, is more intimate than that of the air, with 

 the blood in the lungs, it is even more effectual in its 

 action. In all probability life was first manifested 

 in the water. Many of its simpler forms are yet 

 found there only. The order of their evolution seems 

 to have been from fish to marine reptiles, then to 

 land and flying reptiles ; next, birds ; and, lastly, 

 the mammalia. 



The phenomena of motion, sensation and conscious- 

 ness, faintly and exceptionally existing in plant life, 

 find their full demonstration in the life of animals. 

 The debatable ground occupied by the lower forms 

 the " Monera " of Haeckle has been mentioned, and 

 they have been sufficiently discussed. Even to at- 

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