THEOEIES AS TO THE ORIGIN OF LIFE. 81 



act, equivalent to an act of creation, must be 

 performed." 1 



9. In his work in the same series, Dr. Roget, 

 who was strangely represented by the author of 

 the Vestiges to be in favour of his own peculiar 

 views, as thoroughly condemns the " develop- 

 ment theory." " Whatever may be the appa- 

 rent similarity between one animal and another, 

 during different periods of their respective deve- 

 lopments, there still exist specific differences, 

 establishing between them an impassable barrier 

 of separation, and effectually preventing any 

 conversion of one species into another, however 

 nearly the two may be mutually allied. The 

 essential characters of each species, amidst oc- 

 casional varieties, remain ever constant and 

 immutable." And alluding to Lamarck's pro- 

 position, that there was originally no distinc- 

 tion of species, but that each higher race had 

 originally sprung from a lower, " and that 

 infusorial animalcules, spontaneously formed 

 out of original molecules, gave birth, by succes- 

 sive transformations, to att other animals now 

 existing on the globe," Dr. Roget justly con- 



1 Prout's Bridgewater Treatise, pp. 409, 410. 

 F 



