1 68 VESTIGES OF THE 



species was immediately taken by the next in succession, 

 and so on back to the first, for the supply of which the 

 formation of a new germinal vesicle out of inorganic 

 matter was alone necessary. Thus, the production of new 

 forms, as shown in the pages of the geological record, has 

 never been anything more than a new stage of progress 

 in gestation, an event as simply natural, and attended 

 as little by any circumstances of a wonderful or startling 

 kind, as the silent advance of an ordinary mother from 

 one week to another of her pregnancy. Yet, be it re- 

 membered, the wdiole phenomena are in another point of 

 view, wonders of the highest kind^ for in each of them 

 we have to trace the effect of an Almighty Will which 

 had arranged the whole in such harmony with external 

 physical circumstances, that both were developed in 

 parallel steps— and probably this development upon our 

 planet is but a sample of what has taken place, through 

 the same cause, in all the other countless theatres of 

 being which are suspended in space. 



This may be the proper place at which to introduce the 

 preceding illustrations in a form calculated to bring 

 them more forcibly before the mind of the reader. The 

 table on pages 170, 171, was suggested to me, in conse- 

 quence of seeing the scale of animated nature presented 

 in Dr. Fletcher's " Rudiments of Physiology." Taking that 

 scale as its basis, it shows the wonderful parity observed 

 in the progress of creation, as presented to our observa- 

 tion in the . succession of fossils, and also in the fa^tal 

 progress of one of the principal human organs.* 



* " It is a fact of the higliest interest and moment that as the biain 

 of every tribe of animals appears to pass, during its development, in 

 succession through the types of all those below it, so the brain of 

 man passes throngh the types of those of every tribe in the creation. 

 It ret)resents, accordingly, before the second month of utero-gestation, 

 that of an avertebrated animal ; at the second month, that of au 



