A SUMMER RAMBLE AMONG THE HEBRIDES. 179 



thk occasion, of their dependence on a simple law of instinct, 

 which is as active in producing the same kind of phenomena 

 now as it seems to have been in the earlier days of the Old 

 Red Sandstone. The Cromarty and Moray Friths, mottled 

 with fishing boats (for the bustle of the herring fishers had 

 just begun), stretched out before me. A few hundred yards 

 from the shore there was a yawl lying at anchor, with an old 

 fisherman and a few boys angling from the stern for sillocks 

 (the young of the coal-fish) and for small rock-cod. A few 

 miles higher up, where the Cromarty Frith expands into a 

 wide land-locked basin, with shallow sandy shores, there was 

 a second yawl engaged in fishing for flounders and small skate, 

 -for such are the kinds of fish that frequent the flat shal- 

 lows of the basin. A turbotrnet lay drying in the sun : it 

 served to remind me that some six or eight miles away, in an 

 opposite direction, there is a deep-sea bank, on which turbot, 

 halibut, and large skate are found. Numerous boats were 

 stretching down the Moray Frith, bound for the banks of a 

 more distant locality, frequented at this early stage of the 

 herring fishing by shoals of herrings, with their attendant dog- 

 fish and cod ; and I knew that in yet another deep-sea range 

 there lie haddock and whiting banks. Almost every variety 

 of existing fish in the two friths has its own peculiar habitat ; 

 and were they to be destroyed by some sudden catastrophe, 

 and preserved by some geologic process, on the banks and 

 shoals which they frequent, there would occur exactly the 

 same phenomena of grouping in the fossiliferous contempo- 

 raneous deposits which they would thus constitute, as we find 

 exhibited by the deposits of the Lower Old Red Sandstone. 

 The remains of Holoptychius occur, I have said, in the 

 neighbourhood of Thurso. I must now add, that very singu- 

 lar remains they are, full of interest to the naturalist, and, 

 in great part at least, new to Geology. My readers, votaries 

 of the stony science, must be acquainted with the masterly 



