Species

The Nineteenth Century, a Period of Change 135

James Dana: A Law of Creation

But Agassiz was not alone in pressing the Cuvierian view in the period leading up to
the Origin. His very great admirer James Dana, in an essay in a journal he co-edited,
reiterated the old view that “species” applies to all natural things, and that the vari-
able characters of individuals are merely confusing. To this end, he rejected the idea
that species are even groups, necessarily. Instead, he wrote

A species corresponds to a specific amount or condition of concentrated force, defined

in the act or law of creation.^93

At least in the inorganic world: species are what they were constituted at their
creation to be. In the biological world, the idea is the same, leading to the under-
standing that

[t]he species is not the adult resultant of growth, nor the initial germ cell, nor its condi-

tion at any other point; it comprises the whole history of development. Each species

has its own special mode of development as well as ultimate form or result, its serial

unfolding, inworking and outflowing; so that the precise nature of the potentiality in

each is expressed by the line that historical progress from the germ to the full expan-

sion of its powers, and the realization of the end of its being. We comprehend the

type-idea only when we understand the cycle of evolution [sensu development—JSW]

through all its laws of progress, both as regards the living structure under development

within, and its successive relations to the external world.^94

For Dana, species are the units of the organic world as molecules are the units of
the inorganic. He discusses the ranges of infertility of hybrids from the infertile mule
to the continuously fertile hybrid, and says that the fully fertile hybrid is not observed
in nature, at least among animals; plants are more frequently hybridizing. In a rather
backhanded manner, he affirms the monogenist position—humans are one species,
although non-white races are disappearing

... like plants beneath those of stronger root and growth, being depressed morally,

intellectually and physically, contaminated by new vices, tainted variously by foreign

disease, and dwindled in all their hopes and aims and means of progress, through an

overshadowing race^95

lest any of his readers get the wrong idea. At least he stood up to Agassiz on
monogenism.
Species are not transmutable, for all hybridization is merely recombination of
already extant variation, but there is variation within species—the unfolding of the
potentiality inherent within a species according to natural law and changing cir-
cumstances.^96 Species are liable to variation as part of the law of a species, and

(^93) Da na 1857, 306, italics original.
(^94) Da na 1857, 308.
(^95) Dana 1857, 311.
(^96) Dana 1857, 312.