THE OLD RED SANDSTONE. 241 
when struck fresh from the surrounding lime, reflects the pris- 
matic colors, as of old; a huge Modiola still retains its tinge 
of tawny and yellow; and the fossilized wood of the forma- 
tion preserves a shade of the native tint, though darkened 
into brown. But there is considerably less of color in the 
fossils of the Old Red Sandstone. I have caught, and barely 
caught, in some of the newly disinterred specimens, the faint 
and evanescent reflection of a tinge of pearl; and were I ac- 
quainted with my own collection only, imagination, borrowing 
from the prevailing color, would be apt to people the ancient 
oceans, In which its forms existed, with swarthy races exclu- 
sively. But a view of the Altyre fossils would correct the 
impression. They are enclosed, like those of Cromarty, in 
nodules of an argillaceous limestone. The color, however, 
from the presence of iron, and the absence of bitumen, 1s 
different. It presents a mixture of gray, of pink, and of 
several minutes before either would give way; and when one does 
submit, imagination can hardly conceive the vindictive fury of the 
conqueror, who, in the most persevering and unrelenting way, chases 
his rival from one part of the tub to another, until fairly exhausted 
with fatigue. From this period an interesting change takes place in 
the conqueror, who, from being a speckled and greenish-looking fish, 
assumes the most beautiful colors ; the belly and lower jaws becoming 
a deep crimson, and the back sometimes a cream color, but gener- 
ally a fine green, and the whole appearance full of animation and 
spirit. I have occasionally known three or four parts of the tub 
taken possession of by these little tyrants, who guard their ter- 
ritories with the strictest vigilance, and the slightest invasion 
brings on invariably a battle. A strange alteration immediately 
takes place in the defeated party: his gallant bearing forsakes 
him, his gay colors fade away, he becomes again speckled and 
ugly, and he hides his disgrace among his peaceable compan- 
ions.’”’ 
23 * 
