. The chain of life in geological time [microform] : a sketch of the origin and succession of animals and plants. Paleontology; Paleobotany; Paléontologie; Paléobotanique. i6 THE CHAIN OF LIFE. i h-i m resisting rocks can be best seen as impressed moulds on tlie weathered surfaces. Lastly, we sometimes have impressions or footprints repre- senting the locomotion of fossil animals, rather than the fossils themselves. In this way some extinct creatures are known to us only by their footsteps on sand or clay, once soft, but now hardened into stone; and in the case of some of the lower animals the
. The chain of life in geological time [microform] : a sketch of the origin and succession of animals and plants. Paleontology; Paleobotany; Paléontologie; Paléobotanique. i6 THE CHAIN OF LIFE. i h-i m resisting rocks can be best seen as impressed moulds on tlie weathered surfaces. Lastly, we sometimes have impressions or footprints repre- senting the locomotion of fossil animals, rather than the fossils themselves. In this way some extinct creatures are known to us only by their footsteps on sand or clay, once soft, but now hardened into stone; and in the case of some of the lower animals the trails thus made are often not easily interpreted (Figs. 12, 12a). It has been found that even sea-weeds drifted by the tide make impressions of this kind, which, when they occur in old rocks, are very mys- terious. Even rain-drops are capable of being permanently impressed on rocks, and con- stitute a kind of fossils. Be- sides these we have many kinds of imitative markings which simulate fossils, as those of concretions or no- dules, which are often very fantastic in shape, those 01 dendritic crystallisation giv- ing moss - like forms, and the complicated tracery pro- duced on muddy shores by the little rills of water which follow the receding tide (Fig. 13). Such things are often mistaken by the ignorant for fossil remains, but are easily distinguished by a practised eye. The reader who has followed these, perhaps somewhat dry, details, will be rewarded for his patience by having some. Fig. II.—Cast of erect tree {Sii^illaria) in sandstone, standing on a small bed of coal, South Joggins, Nova Scotia (Daw- son's Acadian Geology).. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Dawson, J. W. (John William), Sir, 1820-1899. London : Religious Tract Society
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectpaleontology, bookyea
