LIFE ON THE EARTH. 11 



But in general, there is the preparation of egg or 

 seed, the development of these in connection with 

 nutritive matter prepared in each, and the passage 

 through several stages before the complete state 

 of individual life is attained ; then recurs the separa- 

 tion of parts impressed with the wonderful power, 

 and subject to the inconceivable restraint, of so 

 acting on and being acted on by the elementary 

 powers around, as to grow, reproduce and decay, 

 in forms and through periods corresponding to those 

 appointed for their ancestral races since time began. 



INFLUENCE OF CLIMATE ON THE DISTRIBUTION 

 OF LIFE. 



Not the whole surface of the earth is occupied 

 by living beings. Notwithstanding the perpetual 

 struggle to diffuse their seed, plants do not cover all 

 the regions of the land ; nor is the amazing fertility 

 of many marine animals able to carry life into all 

 parts of the sea. The geographical distribution of I 

 plants and animals, a subject of great richness and 

 instruction, offers some general facts which must 

 not be neglected in reasoning on the ancient forms 

 of life which fill the stratified rocks. 



Among the most influential of all the causes 

 which limit the ranges of life is temperature. The 



