118 GEOLOGICAL MEMOIRS. 



served with regard to subsequent periods. Thirdly^ that if the pa- 

 laeozoic species differed more according to place and climate than 

 has been generally supposed, there is still a greater uniformity in 

 the types to which they must be referred than is the case at present, 

 whence we may conclude that the animal creation was indeed then 

 distributed as it is now into geographical groups, but that these 

 groups were then less distinct from one another, owing to a greater 

 uniformity in the climate in different parts of the earth. Fourthly^ 

 that the great laws which governed the introduction and extinction 

 of species were the same in Russia as in the rest of Europe. And 

 fifthly i that the species which traverse several systems of deposits 

 are generally those which appear most widely distributed in distant 

 countries. 



Lastly, if we bring the palaeozoic fauna generally into contrast 

 with the existing fauna, we find differences which involve not only 

 a change in species, but an entirely distinct grouping of the animal 

 kingdom. We learn that many classes, and amongst them the high- 

 est in the series, had not yet appeared upon the earth ; that most of 

 the genera were different from those now represented ; that those 

 which have been continued to our time exhibit in the relative num- 

 ber of their species a totally different and often inverse proportion ; 

 and lastly, that the actual population of the globe is by no means the 

 remnant of a population formerly more extensive. At the same time 

 we are forced to abandon the idea, that the first created beings ex- 

 hibited merely the first rough and unfinished outline of the plan of 

 nature ; and if there has been any progressive movement in creation, 

 such as the successive introduction of the different classes of the 

 vertebrate animals, it is important to observe that the products of 

 creative power, whatever rank may be assigned them, have at all 

 times exhibited that admirable perfection which belongs to every- 

 thing proceeding from the hands of the Creator. 



D. T. A, 



