148 THE CREATION OF MATTER 



and took the world of science by storm. With limita- 

 tions and professions of uncertainty as to all the factors, 

 it is now very generally accepted, though few ascribe to 

 it the range and power in which Haeckel exults. He 

 makes it everything. He regards it as sufficient, through 

 the mighty power of carbon, to account for the most 

 complex phenomena of existence. 



The chief principles of Darwin's theory may be stated 

 briefly. There is 



1. TJie law of heredity or likeness of offspring to 

 parents. Like invariably produces like. No law is 

 more universally known and acknowledged. The seeds 

 of a plant grow into the same plant. The eggs of an 

 animal grow into the same animal form. 



2. The law of variation. " No being on this earthly 

 ball is like another all in all." In every species of 

 plants and animals individuals tend to vary from the 

 specific type. No plant is wholly like another plant. 

 No animal offspring, in all respects, resembles its parents 

 or any other individual to which they give birth. There 

 are variations generally in every organ, in every appear- 

 ance, throughout whole bodies. In some cases the varia- 

 tions are considerable. By the law of heredity these 

 variations are transmitted. A new species of short-legged 

 sheep was produced in America at a single bound. 



3. Tlie law of multiplication by geometrical progression. 

 There is in many plants and animals the possibility of 

 increasing a hundred- or even a thousand-fold in a single 

 year. 



4. The law of limited populations. The number of 

 every species is limited by the conditions or nature of the 

 environment in which it lives, by the amount of food in 

 it, and by the number and strength of the enemies which 

 it has to encounter. A plant or tree may produce seeds 



