NA TURA L HIS TOR V OF CREA TION. 1 5 5 



presume that, in this case, the simple engender the 

 comphcatecn Undoubtedly, this would not be more 

 vvo-nderful as a natural process than one which we never 

 think of wondering at, because familiar to us — namely, 

 that in the gestation of the mammals, the animalcule-like 

 ovum of a few days is the parent, in a sense, of the chick- 

 like form of a few weeks, and that in all the subsequent 

 stages — fish, i-eptile, Arc. — the one may, with scarcely a 

 metaphor, be said to be the progenitor of the other. 

 1 suggest, then, as an hypothesis already countenanced 

 by much that is ascertained, and likely to be further 

 sanctioned by much that remains to be known, that the 

 first step was an advance under favour of j)<icidiar condi- 

 tions, from the siuij^lest forms of beiiig, to the next more 

 complicated, and this throiKjh the 'medium of the ordinary 

 process of generation. 



Unquestionably, what we ordinarily see of nature is 

 calculated to impress a conviction that each species 

 invai'iably produces its like. But I would here call 

 attention to a remarkable illustration of natural law 

 which has been brought forward by Mr. Babbage, in his 

 " Ninth Bridgewater Treatise." The reader is requested 

 to suppose himself seated before the calculating m.achine, 

 and observing it. It is moved by a weight, and there is 

 a wheel which revolves through a small angle round its 

 axis, at short intervals, presenting to his eye successively, 

 a series of numbers engraved on its divided circum- 

 ference. 



Let the figures tluis seen be the series, i, 2, 3, 4, 5, 

 itc, of natural numl^ers, each of which exceeds its imme- 

 diate antecedent by unity. 



•■• Now, reader," says Mr. Babbage, '■ let me ask you 

 how long you will have counted Ijefore you are firmly 

 convinced that the engine lias been so adjusted, that it 



