UNITY OF DESIGN. /J45 



birds and mammalia, and the Cetacea, between fislies and 

 warm-blooded quadrupeds: for these are but detached links 

 of a broken chain, tending, indeed, to prove the unity of the 

 designs of Nature, but showing also the specific character of 

 each of her creative efforts. The pursuit of remote and 

 often fanciful analogies has, by many of the continental phy- 

 siologists, been carried to an unwarrantable and extravagant 

 length: for the scope which is given to the imagination in 

 these seductive speculations, by leading us far away from the 

 path of philosophical induction, tends rather to obstruct than 

 to advance the progress of real knowledge. I3y confining 

 our inquiries to more legitimate objects, we shall avoid the 

 delusion into which one of the disciples of this transcenden- 

 tal school appears to have fallen, when he announces, with 

 exultation, that the simple laws he has discovered have now 

 explained the universe;* nor shall we be disposed to lend a 

 patient ear to the more presumptuous reveries of another 

 system-builder, who, by assuming that there exists in or- 

 ganized matter an inherent tendency to perfectibility, fan- 

 cies that he can supersede the operations of Divine agency. t 

 Very different was the humble spirit of the great New- 

 ton, who, struck with the immensity of nature, compared 

 our knowledge of her operations, into which he had himself 

 penetrated so deeply, to that of a child gathering pebbles on 



• *' L'univers est expllque, et nous le voyons; c'est un petit nombre de 

 prlncipes generaux et feconds qui nous en ont donne la clef." Serrcs, Ann. 

 des So. Nat. xi. 50. 



f Allusion is here made to the celebrated theory of Lamarck, as exposed 

 in his "Pliilosophie Zoolog-ique. " He conceives that there was orig-inally 

 no distinction of species, but that each race has, in the coui-se of ages, been 

 derived from some other, less perfect than itself, by a spontaneous effort at 

 improvement; and he supposes that infusorial animalcules, spontaneously 

 formed out of organic molecules, gave birth, by successive ti-ansformations, 

 to all other animals now existing on the globe. He believes that tribes, ori- 

 ginally aquatic, acquired by their own efforts, prompted by their desire to 

 walk, both feet and legs, fitting them for progression on tlie ground; and 

 that these members, by the long contiinicd operation of the wish to flv, were 

 transformed into wings, adapted to gratify that desire. If this be philoso- 

 phy, it is such as might have emanated from the college of Laputa. 



