316 ON THE DEPOSITS CALLED TERTIARY 



its rivers, a similar series would occupy that cavity, 

 which would then be a huge basin of tertiary strata. 

 On a small scale, this fact is abundant in Scotland : 

 we need not go further to seek for what may be called 

 Lacustral fresh water formations. And this forms an 

 intelligible division ; demanding a class for itself, as 

 far as the difference between fresh water and salt is 

 entitled to claim two classes. 



If we turn to the Caspian sea, and reason on it in 

 the same manner, the same conclusions follow ; and 

 we may thus form a division or class of Lacustral 

 marine formations. The qualities of the strata might 

 possibly differ, or they might not ; but the striking 

 difference to a zoologist, would be found in the nature 

 of the organic fossils. They would be marine, as far 

 as such distinctions are secure and assignable. But 

 another event would happen in this case : and thus 

 would follow a distinction, the nature, and value, 

 and causes of which have been strangely misap- 

 prehended, under that mixture of an ignorance seek- 

 ing for causes where they were not to be found, and 

 that love of the marvellous which has been far too 

 predominant in geology. Where the rivers enter, 

 the organized beings of fresh water would be depo- 

 sited ; and they would also be deposited under inun- 

 dations, through transportation. It is the exact 

 parallel to the 'destuary of a river ending in the ocean; 

 and thus would there be mixtures and alternations of 

 marine and fresh water fossils, of animals and of 

 vegetables. And further, as such lakes are main- 

 tained in a state of saltness, only because they have 

 no exit, it is conceivable, from known facts, that such 

 an exit might have occurred after a certain time; in 

 which case a salt lake would be followed by a fresh 

 one in the same place, whence also there would 



