2 It) Prof. J. Van der Hoeven on the Succession and 



to have a great charm for the minds of most persons, that there 

 is an unbroken chain of progression in all the productions of 

 organized nature, and that there is an imperceptible transition 

 from the one to the other, all being connected, without any 

 jump*. It would not be difficult to refute many of the proofs 

 which are often brought forward in favour of this connected 

 series; but this refutation could have no other value than that 

 of evincing that the examples were ill-chosen and delusive. It 

 will be sufficient to remark that the existence of such an unin- 

 terrupted ladder is by no means a necessary consequence of the 

 incontestable diversity in complication and perfection of the 

 organisms, and that there can be degrees of perfection without 

 an imperceptible transition from one to the other. 



The conception of an uninterrupted ascending series assumes 

 a very different character when it is connected with the opinion 

 that there is really such an evolution from the most simple beings 

 to the highest organisms. Many authors use the word " evolu- 

 tion," or development in the different divisions of the animal 

 and vegetable kingdoms, only in a metaphorical sense; but 

 others believe that there is really such a gradation, and that the 

 great variety of organic bodies originates in a succession of 

 developments. According to these authors, a more complicated 

 organism is the descendant of another not so complicated, and 

 this organism, again, was the* offspring of a still more simple 

 one; and in this manner, by a continuous progression from 

 step to step, we arrive at last at unicellular forms, as the original 

 prototypes and progenitors of the whole animal and vegetable 

 kingdoms. In this conception the transitions ought to be alto- 

 gether complete, and it seems that even the smallest chasm can- 

 not exist. If it appears that there are, nevertheless, such chasms, 

 it must be surmised that many living species still escape our re- 

 searches, and our imperfect knowledge is the only reason of this 

 apparent discontinuity — or that these connecting links existed 

 formerly, but are now destroyed by some revolutions in the con- 

 dition of the globe, and thus removed from our actual observation. 



If we withdraw from the bright field of inquiry which is illu- 

 mined by observation, and deviate into the gloomy labyrinths 

 of opinion, it is not uncommon to behold all sorts of representa- 

 tions, which assume other forms and dissolve away like the con- 

 fused outlines of the clouds. It is in this manner alone that we 

 find an explanation of the arbitrary conceptions proposed by 

 some authors, as if they were events of the history of creation. 

 Amongst the authors who are the adherents and advocates of 

 such an evolution of organisms as I allude to, a first place ought 



* It was principally Charles Bonnet who enlarged upon this scheme, 

 and extended the^ conception to the universe. 



