2&1 FOSSIL FOOTSTEPS. 
would ill no way interfere with the preserva- 
tion of impressions made by feet, and speedily 
filled up by a succeeding deposit of sand, which 
would assume, with the fidelity of an artificial 
plaster mould, the precise form of the surface to 
which it was applied. 
Notwithstanding this absence of bones from 
the rocks which are thus abundantly impressed 
with footsteps, the latter alone suffice to assure us 
both of the existence and character of the ani- 
mals by which they were made. Their form is 
much too short for the feet of Crocodiles, or any 
other known Saurians ; and it is to the Testu- 
dinata, or Tortoises, that we look, with most 
probability of finding the species to which their 
origin is due."^ 
The Historian or the Antiquary may have 
traversed the fields of ancient or of modern 
* This evidence of footsteps, on which we are here arguing, is 
one which all mankind appeal to in every condition of society. 
The thief is identified by the impression which his shoe has 
left near the scene of his depredations. Captain Parry found 
the tracks of human feet upon the banks of the stream in Pos- 
session Bay, which appeared so fresh, that he at first imagined 
them to have been recently made by some natives : on examina- 
tion they were distinctly ascertained to be the marks of the shoes 
of some of his ov/n crew, eleven months before. The frozen con- 
dition of the soil had prevented their obliteration. The Ameri- 
can savage not only identifies the Elk and Bison by the 
impression of their hoofs, but ascertains also the time that has 
elapsed since each animal had passed. From the Camel's track 
upon the sand, the Arab can determine whether it was heavily or 
lightly laden, or whether it was lame. 
