198 THE LAW. 



If by the former process, where is the finely graduated 

 scale of transitional forms, either living or fossil ? And if 

 by the latter, how comes it to pass that we have not a 

 universal uniformity of life-type at the successive stages of 

 geological time ? for we cannot conceive of any mere phy- 

 sical law acting with discrimination, and peopling one region 

 with one set of forms, and another region with other classes 

 and orders. If it shall be argued that the physical condi- 

 tions of one region differ from those of another, and must 

 necessarily be accompanied by a diversity of results, we 

 restrict our reasonings to any one area, and there we find as 

 great a complexity and variety characterising the part as the 

 advocates of this hypothesis can demand for the whole. 

 Some forms continue persistent and unchanged, others die 

 out and are succeeded by closely allied forms ; some remain 

 scanty and localised, while others increase and largely ex- 

 tend their boundaries; and this under precisely the same 

 conditions and in the self-same area a fact altogether in- 

 explicable were the influence of external conditions the 

 only factor in the law of vital diversity. 



As to " intermediate or gradational forms," let us 

 take care also that we do not mistake functional re- 

 semblance for genetic affinity, and simulative forms for 

 identities. That we have quadrupeds, like the orni- 

 thorhyncus, partaking of some of the characteristics of 

 birds ; mammals, like the whale, modified so as to as- 

 sume the aspect of fishes; fish-like reptiles, as the ichthy- 

 osaurus; and reptile-like fishes, as the rhizodus, no one 

 for a moment gainsays. These, however, are mere func- 

 tional resemblances, not genetic affinities ; the modification 

 of the great aboriginal types, so as to adapt them for every 

 element air, earth, and ocean and to fit them for the 

 performance of every function which the conditions of the 

 world, for the time being, might require. The whale, 



