136 ON THE REVOLUTIONS Of 



the formations of which we have been speaking are contained, but 

 the borders of which they also cover in those places where they were 

 less elevated. 



In fact, it is not in our basin alone that these kinds of formations 

 are deposited. In other countries, where the surface of the chalk 

 offered similar cavities ; in those even where there was no chalk, and 

 where the most ancient formations alone offered themselves as sup- 

 porters, circumstances often brought deposites more or less like our 

 own, and containing similar organic bodies. 



Our fresh-water shell formations of the second stage have been 

 found in England, Spain, and even to the confines of Poland. 



The marine shells placed between them have been discovered along 

 the whole chain of the Appenines. 



Some of the quadrupeds of our gypsum deposites, the palseotheria, 

 for instance, have also left some of the remains in the gypseous forma- 

 tions of Velai, and in the molasse quarries of the south of France. 



Thus the partial revolutions which took place in our environs, be- 

 tween the epoch of the chalk and that of the general deluge, and 

 during which the sea was thrown upon our districts or retired from 

 them, occurred also in a multitude of other countries. The globe 

 underwent a long series of variations and changes, probably very rapid, 

 since the deposites they have left nowhere show much thickness or 

 solidity. The chalk was produced by a sea more tranquil and unin- 

 terrupted ; it contains only marine productions, amongst which there 

 are, however, so7ne vertebrated animals of most peculiar kinds ; but the 

 whole class of reptiles and fishes, great tortoises, enormous lizards, 

 and similar animals. 



The formations previous to the chalk, and in the hollow of which 

 it is deposited, as the layers of our neighbourhood are, form a great 

 part of Germany and England ; and the efforts recently made by the 

 learned of these two countries, similar to ours, and by employing the 

 same principles, united to those which had been previously tried by the 

 school of Werner, will soon leave nothing to be desired in addition to 

 our knowledge of them. MM. Humboldt and de Bonnard in France 

 and Germany, Messrs. Buckland and Conybeare in England, have 

 given us the most perfect and complete tables of them. 



The table annexed, which was kindly drawn out for me by M. 

 de Humboldt, to adorn my work, not only has the secondary forma- 

 tions, but the whole series of strata arranged from the most ancient 

 that are known, to the most recent and superficial. It is in a manner 

 the summary of the labours of all geologists. 



