ANIMALS OF LONG AGO 369 



Nature, quite unintentionally, has been kind in preserving 

 memorials of the past. More have perished than have been pre- 

 served, but the investigator is thankful for what he is able to find. 

 From what has been discovered we are able to form some concep- 

 tion of the history of this world of ours and, in imagination, 

 reconstruct the past. It is remarkable that we have so much 

 evidence to work upon, that remains ages old have not utterly 

 perished. As Emerson wrote: "Nature will be reported. All 

 things are engaged in writing their history. The planet, the pebble 

 goes attended by its shadow. The rolling rock leaves its scratches 

 on the mountain ; the river, its channel in the soil ; the animal, its 

 bones in the stratum ; the fern and leaf, their modest epitaph in 

 the coal. The falling drop makes its sculpture in the sand or stone. 

 Not a foot steps into the snow, or along the ground, but prints, 

 in characters more or less lasting, a map of its march . . . the 

 ground is all memoranda and signatures ; and every object covered 

 over with hints, which speak to the intelligent." 



Ripple marks made by the waves of the sea on shore sands 

 millions of years ago are sometimes observable on sandstones ; even 

 the processes of solidification of the sand into rock, and a super- 

 imposed weight of millions of tons of strata, have not been suffi- 

 cient to remove the evidence of the action of those ancient waves. 

 The footprints of birds and reptiles have made impressions so 

 lasting that they still remain, and are a testimony in stone of the 

 life-forms that existed in the period the rocks they are associated 

 with represent. Even raindrop impressions on mud, and sun-cracks 

 made untold ages ago may be detected by the practised eye of the 

 geologist. Pieces of the huge horsetail plants and club-mosses 

 of Carboniferous times fell into streams and were carried by them 

 into lakes where they were covered by mud and sand washed from 

 the land : to-day we find them fossilized in our sandstone quarries, 

 can recognize them, tell what they were, and imagine their story. 

 The preservation of animal remains in sedimentary deposits is easily 

 accounted for. Carcasses of animals are often drifted by rivers in 

 flood into estuaries, seas and lakes, where their flesh gradually 

 disappears, but the harder bones are preserved in sedimentary 

 matter which gradually accumulates about and above them. Bodies 

 of ancient beasts were carried into lakes and seas in a similar manner. 

 The sediment with which they were covered has now become rock. 

 Such sediment is often deposited in great quantities at a remarkable 



