110 Prof. Pictet on (he Succession of Organised Beings 



opinion adopted as to its extension, this important law appears to me 

 unquestionable in its general sense, and it cannot be seriously dis- 

 puted if it be discussed on the foundation where I have placed it. 



I now proceed to the discussion of the theory of successive creations^ 

 a discussion which the analysis I have made will greatly abridge and 

 facilitate. 



The law of the specialty of fossils being established, at least within 

 the limits indicated above, and numerous observations having removed 

 all doubt that different very strongly-marked types have characterised 

 certain geological epochs, and are altogether wanting in the others, 

 palaeontologists have come to recognise the existence of a certain num- 

 ber of distinct faunas, and have endeavoured to explain their succession, 

 that is, to give an account of the phenomena which must have oc- 

 curred on the globe by leaving those numerous remains, so regularly 

 associated, as the marks of their passage. 



The question does not here relate to a simple generalisation of facts, 

 but to hypotheses more or less probable, among which it remains for 

 me to shew, that the theory of successive creations is the only one of 

 all that have been proposed that is admissible, that in its general 

 expression it agrees very well with facts, and that the objections 

 brought against it bear, not on its existence, but rather on the degree 

 of generality and extension which should be conceded to it. 



If we examine all the opinions which have been brought forward 

 with the view of explaining the cause which has associated fossils in 

 the order we now see them, we find only three worthy of attention. 



The first, that of successive extinctions, still supported of late 

 years by a skilful anatomist, assumes that all animals have been 

 created at once, and that they all lived together on the earth ; but 

 that various catastrophes (deluges, upheavals, changes of tempera- 

 ture, &c.) have successively caused a certain number of species dis- 

 appear. Each of these destroyed species has, in consequence, left its 

 remains in the formations made before its extinction, and the traces 

 of it are wanting in posterior formations. According to this hypo- 

 thesis, there have only been successive extinctions, such as those we 

 can observe even in our own day, in regard to some species which 

 have recently disappeared, or will soon do so, from our continents. 

 This theory, attractive by its simplicity, is diametrically opposed to 

 the entire amount of facts with which we are acquainted. Before 

 it could be admitted, it would be necessary that we should find some 

 existing species in the formations of the different epochs ; it would 

 be necessary that the bones of the mammifera of the eocene forma- 

 tions should be mingled with those of species now living — that along 

 with the gigantic reptiles of the secondary epoch, we should find the 

 present inhabitants of our seas — that the ganoid fishes of the ancient 

 formations should be associated with the cycloides and ctenoides — 

 that the silurian and devonian deposits should contain, along with 



