EARLY REPTILIAN FOSSILS. 



239 



pachyderm, for instance, to the terrestrial, from the otary 

 to the otter, from certain phocae to the bear, and so on. 

 There is a unity in all instances in the moral as well as 

 physical characters of the various members of one stirps; 

 we only see it advancing from low to high characters, 

 just as we see the foetus of a high animal passing through 

 various inferior stages before it reach its proper mature 

 character. The lines, moreover, being independent of 

 each other, and not quite uniform as to the stages of 

 animality through which they pass, it follows that, un- 

 less we know of some law governing their different ges- 

 tative periods, we are not entitled to look for the first 

 occurrence of their various ichthyic, reptilian, and mam- 

 malian sections, in any order as regards each other, even 

 though we could be sure (which we are not) that we are 

 surveying a geographical region where they all started 

 fair in the race of progressive organization. Hence it is 

 that, though the batrachia are usually placed by zoologists 

 at the bottom of the list of reptilian orders, I attach little 

 importance to their vestiges being now found so low All 

 that I think we can expect is, that, in a particular area 

 where we have reason to believe that the lines have 

 started abreast, they should all reach their various grades 

 nearly about one time, or what may be considered as one 

 time compared with the whole extent of geological chro- 

 nology. And such appears to be pretty much the case 

 in those regions which geologists have explored. 



The Edinburgh reviewer will observe that this view 

 of the animal kingdom leaves much of his opposition 

 in a very awkward predicament. He has everywhere 

 assumed that the genealogy of the orders of each class 

 was supposed to be en suite, which it certainly never 

 was in my book. In the early editions I spoke with diffi- 

 dence of the course of the supposed development,* be- 

 cause I had not then seen or conceived any arrangement 

 of the animal kingdom which answered to that hypothe- 

 sis, although I thought proper to attempt to show that 

 the quinarian and circular classification, which I found 

 in vogue at the time when I was writing, did not neces- 

 jarily militate against it. In the third edition, the pres- 



* " . . .it does not appear that this gradation passes along one 

 line, on which every animal form can be, as it were, strung ; there 

 may bo branching or double lines at some places." &c— Vestiges 

 Is; ed., p. 130 



