PICTET's PALiEONTOLOGY. 53 



forms of structure. Is it not possible that in these first ages of the 

 world, terrestrial animals also existed more highly organized than 

 their marine contemporaries, although their remains either have not 

 been preserved or are still to be discovered ? The existence of didel- 

 phine mammals in the oolites has been made out by the discovery 

 of a very small number of fragments ; and the remains of land ani- 

 mals generally are hardly fossilized, except by sudden deluges and 

 inundations, which are always trifling in their results compared with 

 the slow but unceasing deposits from the water of the sea. May 

 we not yet expect new discoveries in these ancient strata, revealing 

 to us the existence of primaeval animals at present little suspected ? 



"A second observation I would offer is, that when we endeavour 

 to compare the actual state of the globe with the various former 

 creations, we shall find that the highest degree of perfection of or- 

 ganization will not always furnish conclusive results with regard to 

 the perfection of the faunas. 



^' Putting out of the question the presence of man, should we, for 

 instance, assert that the fauna of Asia is superior to that of Europe 

 because its highest point is the orang-outang ; and should we place 

 the fauna of New Holland much below the rest because its mam- 

 mals are almost all didelphine ? Such conclusions would however 

 be nearly as legitimate as some of those which have been established 

 by the comparison of geological faunas." — Vol. i. pp. 76-83. 



Having thus discussed the laws which have been supposed to re- 

 gulate the distribution of fossils, the author proceeds to compare the 

 different theories most in vogue by which it is endeavoured to ex- 

 plain the phaenomena observed. 



" Of these theories there are only two which require to be con- 

 sidered in any detail. But M. Pictet states his own opinion to be 

 that neither of them is satisfactory, and that he looks forward to a 

 better explanation being furnished by the progressive march of 

 palaeontology. 



" The succession of organic beings is explained by some theorists 

 by the transformation of species, assuming that the animals of the 

 ancient formations have become modified by the influence of atmo- 

 spheric and climatal changes, &c. which the globe has undergone, 

 so that the original forms have insensibly become metamorphosed 

 into others, of which the different strata have preserved and handed 

 down the indications, and these forms have at length by successive 

 changes attained their present condition. 



" The other theory supposes a complete destruction of all the spe- 

 cies by each catastrophe which has terminated an epoch, and a new 

 creation at the dawn of the next succeeding epoch. 



" The theory of the transformation of species seems to me totally 

 inadmissible, and diametrically opposed to everything that we learn 

 from the study of zoology and physiology. This theory connects 

 itself, as I have before observed, with the idea of a scale of beings, 

 and that of the gradual advance towards perfection in the succession 

 of geological periods. This indeed is the bond of union, and the 



