This theory he terms the "Derivative Hypothesis." 

 The professor agrees with Mr. Darwin, Lamarck, and others, in repu- 

 diating the idea of any special creative mii-acle on the advent of a new species, 

 and supposes that new species are derived from old by the ordinary process 

 of generation, but that the new species is born, with some more or less marked 

 distinction, from its parent, amounting iu some cases to what we should term 

 a monstrous birth. 



These differentiated beings he regards as varieties which, for some good 

 cause and to supply some necessity in the cosmical economy, ai-e pre-ordained by 

 the Creator, and brought forth by the working of natm-al laws at appointed 

 seasons, and as a rule are produced in regular sequence, and not having an 

 excessive amount of difference from the parent species. 



As a good example of his successively derived species he gives the case of 

 the horse, which was probably derived from the Hipparion, that again from the 

 Paleothere, and so on. 



At first sight the views of Professor Owen might be thought very similar 

 to those of Blr. Darwin ; but on carefully examining the two theories, it will be 

 seen that although both these naturalists regard existing forms as lineal 

 descendants of pre-existing and extinct forms, yet they regard the manner and 

 cause of their being so in very different lights. On one point, however, they 

 agree, that is, to do away with miraculous intervention and attribute new species 

 to the working of natural laws. 



This tendency to refer all cosmical phenomena to natural laws is 

 certainly one of the most marked features of our time ; and I would venture to 

 remark that, although it places the Divine origin of things in one sense further 

 away from us, yet it in no wise lessens the constant miracle of Divine superin- 

 tendence, and in many ways tends to increase our admiiation of creative skill 

 by seeing what mighty results have been evolved from such small beginnings by 

 the almost unobserved workings of natural laws, that is, laws ordained by the 

 Creator. 



But beyond the one great similarity to which I have alluded to there are 

 maay essential points of difference between Professor Owen's theory of deriva- 

 tion and Mr. Darwin's theory of natural selection, and perhaps one of the 

 greatest is that derivation holds that species change in a pre-ordained manner, 

 and by virtue of inherent tendencies thereto. Natiiral selection holds that 

 altered circumstances make the new species by a long course of slight changes. 



The author of the Derivation Hypothesis admits that when once the 

 change has been made by the birth of an organism different from its parent, 

 surrounding circumstances may afifect the new species, and somewhat modify it, 

 but that they are not the first cause of change, and he believes that the new 

 species are brought into the world at a time when conditions of life are suitable 

 for them. Professor Owen believes also that habits are the results of modified 

 structure, and not like Lamarck, that structure is modified by habit. 



