DISTRIBUTE INSECT VAEIETY. 259 



the decay of the rock-incrusting fungus and fucoid, that earliest 

 dawn of aerial and marine existence. These, advancing towards 

 perfection, attain their most atti^active garb chiefly at the repro- 

 ductive season, and then as insensibly fade into the venerable 

 matrix whence they sprung, yielding to the energy that pre- 

 viously sustained them, and leaving their embryos to carry 

 onward the torch of life. But neither the thick forest shades 

 nor the undulating sea-tangle have thus uninterruptedly grown 

 on the acres they now cover, forming ever insensibly increasing 

 beds of brown or black vegetable mould, the mingled debris and 

 germs of things that were. Even the solid ground over which 

 we ramble was certainly at some epoch a wide ocean, and not 

 land, where slimy sea-shells and populous corals, not trees and 

 insects, multiplied — information which is generally attainable 

 for us at the nearest roadside cutting or wayside quarry. 



Indeed, at this day the insensible interchange of sea and land 

 which awoke the wonder of lyric poet and mediseval troubadour, 

 has passed into the domain of stricter science; so that, pro- 

 ceeding back to the earHest hours of terrestrial life, we may 

 confidently see a circulation of water, as clouds, rivers, lakes, and 

 seas, wearing down an early volcanic land of silica, felspar, and 

 mica, and thus forming muddy sediments that gradually become 

 cemeteries of the life that crawls in the lymph, or luxuriates on 

 its borders, and which, by lapse of time, are to be converted into 

 hard fossils entombed in leaf -like layers within the great book of 

 sandstone, limestone, clay, and slate. We may then turn to 

 consider the other co-operating agent, the slow upheaving and 

 depressing, insensibly oscillating, and very clearly traceable 

 along all lines of coast, lake, and river, in Europe, Asia, Africa, 

 or Polynesia ; that in one spot is slowly raising the beach with 

 its shelly muds from the teeming water; and in another often 

 not far distant, gradually depressing the land with its garb of 

 woods, lakes, and their accumulations beneath the sea waves, 

 and so producing alternations of fresh and salt water sediment 

 or strata on the surface of the globe, which thus becomes coated 

 over as a candle repeatedly dipped in the tallow-vat. At the 

 present period this mechanical work of heat is easy of illustration. 

 We witness the , land surface everywhere tracked by water- 

 courses, which wear for themselves distinct hollows, as that 

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