IT EXPLAINS COMETARY PHENOMENA. 263 



their distribution. The hypothesis of evohition, on the 

 other hand, not only allows of the general answer, that 

 they are minor results of the genetic process ; but also fur- 

 nishes us with something like explanations of their several 

 peculiarities. 



And now, leaving these erratic bodies, let us turn to 

 the more familiar and important members of the Solar Sys- 

 tem. It was the remarkable harmony subsisting among 

 their movements, which first made Laplace conceive that 

 the sun, planets, and satellites had resulted from a common 

 genetic process. As Sir William Herschel, by his observa- 

 tions on the nebulge, was led to the conclusion that stars re- 

 sulted from the aggregation of diiFused matter ; so Laplace, 

 by his observations on the structure of the Solar System, 

 was led to the conclusion that only by the rotation of ag- 

 gregating matter were its peculiarities to be explained. In 

 his " Exposition du Systeme du Monde," he enumerates as 

 the leading evidences of evolution : — 1. The movements of 

 the planets in the same direction and almost in the same 

 plane ; 2. The movements of the satellites in the same di- 

 rection as those of the planets ; 3. The movement of rota- 

 tion of these various bodies and of the sun in the same direc- 

 tion as the orbitual motions, and in planes little different ; 

 4. The small eccentricity of the orbits of the planets and 

 satellites, as contrasted with the great eccentricity of the 

 cometary orbits. And the probability that these harmoni- 

 ous movements had a common cause, he calculates as two 

 hundred thousand billions to one. 



Observe that this immense preponderance of probabil- 

 ity does not point to a common cause under the form ordi- 

 narily conceived — an Invisible Power working after the me- 

 thod of " a Great Artificer ; " but to an Invisible Power 

 working afterthe method of evolution. For though the 

 supporters of the common hypothesis may argue that it 



