332 THE DEER OF AMERICA. 
bring them back to greater similitude to the common parent, 
during which their different conditions of life must have estab- 
lished physical peculiarities in each, which would finally become 
hereditary, and these peculiarities must have become multiplied 
and magnified in each with the continuance of time and genera- 
tion, and so the diverging lines would become continually more 
and more separated. It is a divine law stamped on all mat- 
ter, that nothing is stationary ; change, perpetual and unceasing 
change must ever occur, else the work of the Supreme Architect 
would be at last finished, and when finished, his supervising 
care would be no longer required. Such a time, we think, can 
never come, even as to the minutest particle of matter, else it 
would at last arrive as to all things. If the law of change is 
ever active; if destruction and reconstruction are always at 
work, observation tells us that every reconstruction differs in 
some respect, however minute, from all that had been before ; 
the long aggregation of minute changes must in time become very 
great, how great no one may venture to define. The extrac- 
tion of single drops of water would at length dry the bed of the 
ocean; the removal of single grains of sand would displace a 
desert in the course of time. If change is ever continuous, who 
shall fix limits to transformations which may at length occur. 
These are considerations which may be well remembered when 
we approach the present inquiry. 
We all know that there are certain features in the animal 
economy which are comparatively transitory, and so are easily 
obliterated or changed, while others are more persistent, and 
maintain their integrity to a greater or less degree under almost 
all circumstances or conditions. The nearer alike these pecul- 
iarities are found to be on all the individuals of a species, we 
may reasonably conclude the more persistent they are and the 
less change they have undergone during the course of time. 
How long the physical condition of the earth has rendered it 
impossible for these two varieties to intermingle, and so keep up 
an absolute identity, of course it is impossible to conjecture; but, 
at the shortest, it must have been a very long time. At least 
the generations must be counted by very many thousands. 
During that time we first notice that a great change has taken 
place in the size: the western has become much larger than the 
eastern. That one may have increased in size on the western 
continent, while the other has grown smaller on the eastern, at- 
tributable to physical causes, as aliment, climate, or the like, 
