370 SCIENTIFIC ILLUSTRATIONS [Uni 



shrunk by drying before the sand was spread over them. On 

 some shales of the finest texture impressions of rain-drops may be 

 seen, and casts of. them in the incumbent argillaceous sandstones- 

 Having observed similar markings produced by showers, of 

 which the precise date was known, on the recent red mud of 

 the Bay of Fundy, and casts in relief of the same on layers of 

 dried mud thrown down by subsequent tides, Sir Charles 

 Lyell has no doubt in regard to the origin of some of the ancient 

 Connecticut impressions. He has also seen on the mud-flats of 

 the Bay of Fundy the foot-marks of birds (Tringa minuta) which 

 daily run along the borders of that estuary at low water. Similar 

 layers of red mud, now hardened and compressed into shale, are 

 laid open on the banks of the Connecticut, and retain faithfully the 

 impressions and casts of the feet of numerous birds and reptiles 

 which walked over them at the time when they were deposited, 

 probably in the Triassic period. According to Professor 

 Hitchcock, the footprints of no less than thirty-two species of 

 bipeds, and twelve of quadrupeds, have been already detected 

 in these rocks. Thirty of these are believed to be those of 

 birds, four of lizards, two of chelonians, and six of batrachians. 

 The tracks have been found in more than twenty places, scat- 

 tered throughout an extent of nearly eighty miles from north 

 to south, and they are repeated through a succession of beds 

 attaining at some points a thickness of more than a thousand 

 feet, which may have been thousands of years in forming. If 

 we were to-day to observe one shower of rain-drops, or the 

 footstep of an ordinary bird or reptile, we should no doubt con- 

 sider the matter as very unimportant. Yet what significance 

 may attach to these trifles ! The mark of a bird's claw may 

 interpret a page in the grand geological history of the world to 

 some future explorer. These marks look transient. They may 

 be indelibly imprinted in the stony records of the earth. In the 

 moral universe, too, it is also certain that many things are regis- 

 tered in permanent characters which superficial observers may 

 now consider to be trivial. History perpetuates many acts 

 which were supposed to be transient and unimportant, and in 

 later ages the philosopher explains them. Who can place a 

 bound to the influence of any act, even the movement of a 

 bird's claw in the mud ? The voices which speak to us in the 



