HUGH MILLER. XXllU 



and 3-lOths of an inch thick in the stem, and formed a cha- 

 racteristic feature of the Asterolepis, as yet the most gigantic 

 of the ganoid fishes, and probably one of the first of the Old 

 Red Sandstone. In his former researches, our author had 

 found that all of the many hundred ichthyolites which he had 

 disinterred from the Lower Old Red Sandstone were com- 

 paratively of a small size, while those in the Upper Old Red 

 were of great bulk ; and hence he had naturally inferred, 

 that vertebrate life had increased towards the close of the 

 system, — that, in short, it began with an age of dwarfs, and 

 ended with an age of giants ; but he had thus greatly erred, 

 like the supporters of the development system, in founding 

 positive conclusions on merely negative evidence ; for here, 

 at the very base of the system, where no dwarfs were to be 

 found, he had discovered one of the most colossal of its giants. 



After this most important discovery, Mr Miller extended 

 his inquiries easterly for several miles along the bare and un- 

 wooded Lake of Stennis, about fourteen miles in circumfer- 

 ence, and divided into an upper and lower sheet of water by 

 two long promontories jutting out from each side, and nearly 

 meeting in the middle. The sea enters this lake through the 

 openings of a long rustic bridge ; and hence the lower divi- 

 sion of the lake " is salt in its nether reaches, and brackish 

 in its upper ones; while the higher division is merely brackish 

 in its nether reaches, and fresh enough in its upper ones to 

 be potable." The fauna and flora of the lake are therefore 

 of a mixed character, the marine and fresh-water animals 

 having each their own reaches, though each kind makes cer- 

 tain encroachments on the province of the other. 



In the marine and lacustrine floras of the lake, Mr Miller 

 observed changes still more palpable. At the entrance of the 

 sea, the Fucus nodosus and Fiicus vesiculosus flourish in tneir 

 proper form and magnitude. A little farther on the lake, 

 the F. nodosus disappears, and the F. vesiculosus, though 



