CHAPTER I.
ANALYSIS OF THE DIFFERENT METHODS OF DETERMINING ON
IDENTITY AND DIVERSITY OF SPECIES.
S ection I.—Meaning attached to the terms Species—Genera—
Varieties1—Permanent Varieties—Races.
T he meaning attached to the term species in natural history
is very definite and'intelligible. I t includes only the follow^
ing conditions, namely, separate origin and distinctness of
race, evinced by the constant transmission of some characteristic
peculiarity of organization. A race of animals or -'of
plants marked by any peculiar character which has always
been constant and undeviating, constitutes a species*; and two
races are considered as specifically different, if they are distinguished
from each other by some characteristic which the
one cannot be supposed to -have acquired, or- the other to
have lost through any known operation o f; physical causes;
for we are, hence, led to conclude, that the tribes thus dis-:
tinguishedi have not descended from the same original stock.
This is the purport of the word species^ äs it has long been
understood by «writers on different departments: mf natural
history. They agree1 essentially as, to the sense;which théy
appropriate to this term, though they have expressed themselves
differently according as they have blende#ifrèrte<örlëss
pf hypothesis with their conceptions of its meaning,** Thus’
Cuvier, with reference to the animal kingdom^ and not without
an allusion to the favourite speculations of some of his
contemporaries says, “ We are under the necessity of admitting
the existence of certain forms which have perpetuated