118 Dr Fleming on the Revolutions in the Animal Kingdom , 
place in every cultivated region of the earth, each having, with- 
in the very limited period of history or tradition, lost many of 
the original inhabitants. 
When it is considered, that the business of the chace has ever 
been keenly followed by man, from the first stages of society to 
the present day ; that its triumphs have been eagerly sought af- 
ter, and highly prized ; and when these circumstances are uni- 
ted, with the recollection of the numbers of the human race dis- 
persed over the globe, all prosecuting the same purpose, for the 
long period of nearly 6000 years, it does not appear unreasonable 
to con chide, that man has effected many changes in the geogra- 
phical distribution of animals. Perhaps he may have succeeded, 
in the course of this long period of persecution, in completing the 
destruction of several species, the memorial of which tradition 
has failed to preserve, while their remains may yet be traced in 
the newer and perhaps older alluvial deposits. 
However great those changes may have been, in the condi- 
tion of certain species, brought about by human agency, there 
are many other revolutions which have taken place in the ani- 
mal kingdom, over which man could exercise no control. Many 
corals and shells, the bones of fish, reptiles and quadrupeds, are 
imbedded in stone, which have belonged to species which do not 
now exist in a living state on the globe, and which, probably, 
were extinct before man exercised any control. By what cause, 
then, have these revolutions been effected ? 
When we attend to the physical conditions of temperature, 
food, situation, and foes, which must at all times have exercised 
their influence over the existence and geographical distribution 
of animals, it will appear obvious, that a variety of causes (a 
change in one or all of these conditions) may have operated in 
promoting the increase of some species, and in producing the 
decay or extinction of others. Have we, then, any proof of such 
changes in the truths of geognosy, or in the alterations which 
we witness taking place on the surface of the globe ? 
When we look at a river after rain, emptying its contents into 
the sea, we perceive that it has brought along with it a consi- 
derable quantity of gravel and mud, which it deposits in the 
form of bars, sand-banks, or deltas. This mud has been ob- 
tained from the disintegration and wearing down of the rocks 
