able characters in the animal kingdom and those which are
accordingly fitted to distinguish species, consist chiefly in the
general laws or arrangements of the animal economy in each
tribe. |
An objection which is likely to be offered to this remark is,
that the structure of parts is essentially anterior to their funcsr
tions ; that functions are merely the results of organization,
and ought accordingly to be considered in the last place, all
distinctions and classifications being founded, on the structure
of organs.
Such an observation proposed in abstract terms is very
specious, and it would be well founded if our knowledge of
structures were more complete than it is. But in thb present
state of our science, we have frequently no other method of
discerning mostimportant diversities of organization than by
noting the phenomena of functions. Articulate speech is
among the most important attributes of humanity, but this
faculty would, perhaps, never have been demonstrated by anaT
tomieal examination of the human vocal organs, or by a comparison
of the structure of these with corresponding parts in
the orang. Until the organization of living bodies shall have
been so -fully explored as to elucidate in every instance'the
whole capabilities of structure, we must consider functions
as leading facts on which classifications and inferences may-
be founded not less securely than on what we know of organization
itself. Nor does any material difference exist in this-
point of view between the two series of facts.
In general, the most constant peculiarities in the races'"of
animals, and those which accordingly best answer the pur-
pose of specific characters, consist, as I have already observed,
in the great laws which govern the functions of the animal
economy. The physiological characters of race are liable to
few and unimportant deviations. Particular species have, in
general, one limit in regard to the average duration of life,
the circumstances connected with the ^reproduction of their
kind, such as the number of their progeny, the times and
frequency of breeding, among mammifers, the period of
utero-gestation, and among birds, the interval between laying
and hatching eggs. The other natural functions are subject
to the same laws ; tribes of the same species are with some
varieties subject to theisanae diseases* Their animal or psychical
faculties are' equally constant: in general, their
instincts and habits are found, remarkably uniform. Few
if any important diversities in respect to any of these principal
laws of the animal [economy are known to take place within
the limits of one and.the same-fspecies; while, on the other
hand, those tribesTwhich mostvstrongiy fesemble each' other
in outward form, but-' are • y e t specifically distinct, .are>. found
in reality’to differ in the particulars! above-mentioned/.,Such
are the permanent characters of species. There are, indeed,
diversities^ in the internal constitution, as eviiicedi by; the phenomena
of temperament and predisposition, springing-up within
the ra c e ; but these do not interfere with the principal laws1, of
the animal economy. 1, I t is in the external and ddssf essential
parts that varieties principally take place.- In the texture and
co veringSwhether hairy or woolly of the skiny th$ absence'orpre-
sence and- the size-ofl^dms..andfptrher».append%es,^thetdb.feur
or-complexion, and in some instances in the ’number of fingers?
and toes j^-in all these particulars, varieties frequently springi
up within one an d -th e same species* to the?
pf which there; is-, a strong tendency in the; animal economy:
11 Similar,.-observations may be made., piuiatis riiutariclis,
with respect .to the .vegetables reation. The; speeiespf.plants
display, as it is well'known, varieties of the most; striking ap-
pearance; and these';are: confined to the least essential, hut
which are often the most conspicuous parts ofvegetation, while
„the organs of fructification?; are unaffected by such changes,
and retain a permanent character.*
I shall now proceed to inquire, with respect to all these
several particulars, what physiological facts can be -established
that may tend tp illustrate the relations of races
to each other, both i n , the lowers departments of nature
and in mankind, and I shall begin with some of the particulars
in the physical history o f races , which are the most
constant, and which scarcely deviate within the limits o f the
same species. The subject naturally divides itself under the
following heads
* De Candolle, Diet, des Sci. Nat.