as indicated in the Results of Geognosy. 117 
while the newer are but little altered. These circumstances 
lead us to believe, that the strata containing petrifactions were 
once in a state of mud; and that the same process which alter- 
ed the imbedded relics, communicated to the surrounding mat- 
ter its present compact or crystalline structure. 
These facts in the history of animals, which have been ascer- 
tained by the researches of the geologist, lead the inquisitive 
mind to investigate those circumstances which have operated in 
bringing about such mighty revolutions. In conducting the 
inquiry, it is necessary to impose restraint upon the imagination, 
and deliberately to examine the existing causes of chang£ in the 
animal kingdom, in order to comprehend the alterations which 
have already taken place, or to anticipate those which may yet 
be produced. What influence has man exerted in producing 
such changes ? 
The situation in which we are placed in this world, renders 
it necessary for us to attempt the destruction of many races of 
carnivorous animals, to drive them from our dwellings, cut 
them off in their retreats, and prevent them from living in the 
same region along with us. When we begin to keep flocks of 
tamed animals, to plant gardens and sow fields, we expose our- 
selves to the inroads of a greater number of depredators, and 
consequently wage more extensive war. The war waged, in 
the early stages of society, against various animals, is a measure 
of security. With the progress of civilization this war becomes 
an amusement ; and in the absence of those animals really de- 
structive to our interests, we make sport of the death of others 
which are inoffensive. But the employment of the chace is not 
altogether a measure of safety or amusement. We hunt to ob- 
tain food and clothing, and a variety of ornamental and useful 
. articles of life. 
The havock which man thus commits in the animal kingdom, 
has occasioned the extirpation of many species from those coun- 
tries of which they were formerly the natural possessors. In 
this island, since the Roman invasion, some species of quadru- 
peds and birds have disappeared ; and others are becoming every 
year less numerous. Of those which have been extirpated, the 
bear and the beaver, the crane and the capercailzie, may be 
quoted as well known examples. The same changes arc taking 
