156 FOOTNOTES FROM 



mense profusion, waiting but the recurrence of similar 

 atmospheric conditions as existed in former times, to ex- 

 hibit as extraordinary a development. For all we know 

 there may be existing amongst us the germs of other 

 forms of life, ready to develop themselves into new mani- 

 festations of the power and wisdom of God, if it should 

 please Him to adapt the vital envelope of our globe to 

 the uses of other occupants. The present electrical con- 

 dition of the air is admirably adapted for the healthy 

 development of the forms of life that now exist in it ; 

 and so likewise is the water for the organisms that per- 

 vade it. But who can tell what species of plants and 

 animals would succeed the present species, were there 

 but the smallest change effected in the proportions of 

 the constituents of these elements 1 Geology reveals 

 to us the singular fact that, when the air and the water 

 were densely impregnated with carbonic gas during the 

 coal era, an extraordinary development of the humblest 

 forms of animal and plant life was the result. The earth 

 was covered with dense forests of ferns and mosses, and 

 the waters were peopled with myriads of corallines. 

 And were similar conditions of the atmosphere and the 

 water to occur again, or should any change be produced 

 in the existing conditions, the change, while it would 

 prove fatal to the most highly organized of the present 

 race of animals and plants, would stimulate into excessive 

 growth and profusion animals and plants of the simplest 

 construction, which are now kept in check, and occupy 

 but the most obscure and subordinate positions in the 

 ranks of nature's agencies. And if the advent of wide- 

 spread plagues in the middle ages was heralded by the 



