THE GEOLOGIST. 



23 



\ided for the necessities of the inhabitants of the lake, river, or 

 land, we can now assort, by means of their organization and 

 structure, the fresh water tribes from the terrestrial or the marine, so 

 by the like evidence in any of the paist great periods of Geology, 

 we can also, in the like manner determine those three important 

 classes of depositary rocks, by their fossil shells alone. 



Similar inferences are ever to be drawn of ancient conditions, 

 from every other department of Nature, — from birds and fish, 

 mammalia or reptiles, insects or plants, — all display alike the 

 badges of their mundane offices while living ; and, changed into 

 stone, their lifeless fragments appear self-recordant of the events 

 and phases of their existences. Each, like a dimmed half-faded 

 photograph, seems tinged with the lights and shadows of the 

 scenes in which its span of life was past. 



When silently we rest beneath warm and glowing skies, or 

 in easy chair, by winter hearth and cheerful fire, how many a scene 

 comes rolling through the mind — a vast panorama moving on 

 and on — presenting still some fresh familiar scene. How many 

 thousand yards of canvas, how many miles of bright and beautiful 

 painting, are rolled up in that mysterious scroll, the memory. 

 How fresh and vigorous, as we unroll it in our reveries, come forth 

 the prominent faces and features, the endeared or hated spots of 

 bye-gone days, and how time and forgetfulness have scumbled down 

 most of the harsher details into a mysterious and delightful haze, 

 through which those minor groups are faintly seen. How too, by 

 instinctive perceptiveness from what we know, do we enter into the 

 scenes coiled up within the stony forms of plants, and bones, and 

 shells ; how curiously, piece by piece, do the fragments fit together, 

 like the scattered tessellae of a Roman pavement, displaying in the 

 intervals of color, outline, and vacuity, enough to manifest the 

 tracery of the ancient floor, while as a nail, a peg, a bit of stained 

 mortar, or a coin, complete the associations ;— imagination — memory's 

 sister, — re-builds the luxurious villa, and re-peoples it anew. 



So from slight and apparently insignificant incidents are the 

 great pictures of Geology elaborated and designed — and so does 

 imagination in her reveries, not untruthfully and with a feeling 

 very like remembrance, wander through the phases of those 

 wonderful ages which have passed for ever away. Thus does even 



