Henry Woodward — Old Land-surfaces. 499 



day ; nor, that cataclysmic action has effected many important 

 changes in the configuration of land-surfaces in past geological 

 time; yet by far the greatest part of the work performed in 

 Nature's laboratory must be attributed to those humble yet untiring 

 agents — upheaval and denudation, sunshine and shower, snow and 

 ice, heat and cold, ebb and flow, which have never rested night nor 

 day through all the ages of time since the waters were gathered 

 together into one place and the dry land appeared. 



But to return to our subject, had the Coal been accumulated under 

 exceptional conditions of light, heat, and atmosphere, it would be 

 absolutely necessary to exclude animal life from the scene of its 

 formation. 



Such, however, was not the case, for in the progress of geological 

 discovery we have become acquainted with no fewer than 30 species 

 of land-dwelling, or amphibian reptiles, 150 fishes, more than 12 

 species of insects, two myriapods, two scorpions, a Eurypteriis, six 

 species of King-crabs, a host of Entomostraca, one or more Macrouran 

 Decapod, two land-snails, besides Unionidce and a host of other 

 Mollusca. 



There are evidences of sunshine in the flowering organs,^ called 

 Antholithes, and in the ripened fruits and seeds ; of shower in the im- 

 pressions of raindrops on the mud ; of tides in the ripple-marked 

 eandstoues, covered also with the impress of the feet of the reptilia, 

 which must have swarmed along the Carboniferous shores and rivers. 



Nor were these wooded shores destitute of melody, for albeit, no 

 bird (so far as we yet know) built its nest there, the familiar chirp 

 of the cricket was already to be heard, whilst the hum of the many 

 winged insects enlivened the solitudes of these strange old forests. 



We have referred to the numerous beds of Coal occurring in the 

 South Wales Coal-field, but in the cliffs of the South Joggins in 

 Nova Scotia the total thickness of Coal strata is not less than 14,570 

 feet. In a space of 1400 feet Dr. Dawson noted no fewer than 

 sixty -eight root-bearing soils ; and erect trunks have been ob- 

 served at seventeen different levels. (See Dr. Dawson's "Acadian. 

 Geology.") 



The Coal-strata here, it should be observed, are exposed in a long 

 sea-cliff, and are tilted up at an angle of 24° ; but the trees stand at 

 right angles to the " dirt-bed " or soil in which they grew. 



Various are the hypotheses which have been offered in explanation 

 of the accumulation of the successive beds of the Coal in horizontal 

 superposition. The most plausible hitherto propounded are : — (1st). 

 Coal was accumulated in the wide alluvial plains and deltas of great 

 rivers, such as the Amazons, the Mississippi, the Ganges, or the Yang- 

 tse-Kiang river. In the Mississippi, four or more buried forests have 

 been observed superimposed one upon another, with their underclays 

 or root-beds and the erect Cypress-trees buried in drift and mud. 



(2nd). The Mangrove swamps along tropical insular coasts. In 

 the former case the layers of vegetation are covered by freshwater 



^ Indeed uo p-een leaf can be formed without sunlight, for the Chlorophyll is not 

 developed in plants living in the dark or shade. 



