Species

The Nineteenth Century, a Period of Change 143

Prince Charles Lucien Bonaparte (1803–1857), nephew of the famous Napoleon,

was an active ornithologist, as his father Lucien had been after the British released

him from detention in 1814. Exiled in Leiden by his cousin Louis Napoleon, he

became friends with Hermann Schlegel, another famous ornithologist.^134 In 1851 he

published the first volume of his Conspectus generum avium, a survey of all known

species of birds worldwide. In this work, he treated extant species as the descendent

forms of prior extinct forms, and in an address to an 1856 convention on “What is a

species, particularly in ornithology?” he said:

We will state with unanimous conviction that the antediluvian crocodiles, elephants

and rhinoceroses were the ancestors of those living in our day, and these animals

would not have been able to continue to exist without the manifold mutations that

their systems produced to adapt themselves to the environment, and that became

second nature to their descendants. ... If the environment remains the same, so

do the species. The stabilizing influence is then by itself all-powerful. The mutat-

ing influence can succeed in opposing it only when the whole world surrounding

it changes. ... But races, however different in characteristics they may be, vanish

entirely or at least do not long survive as soon as the environment that produced

them ceases to be the same ... The transitions between the different races and their

type are the best evidence that we can supply to set aside putative species, which

are to be relegated to races, with which the painstaking zoologist must nevertheless

occupy himself just as earnestly.^135

Of interest in this excerpt is the implication that species are racial groups stabi-

lized by the influence of the environment, somewhat as stabilizing selection oper-

ates (although there is no reason to suppose Bonaparte thought selection was the

reason for the stabilization). As Darwin later also argued, races are merely species

in the making that are not yet made stable. Bonaparte died in 1857, leaving the

Conspectus unfinished.

Franz Unger, an Austrian botanist at the University of Vienna, published a form

of common descent with modification theory in 1852, entitled “Attempt at a History

of the Vegetable Realm” (Versuch einer Geschichte der Planzenwelt) in which

he supposed that all plant life was a single entity that had developed new forms.

Unger’s theory is often taken to be a forerunner of Darwin,^136 but he in fact thought

that all subsequent development was an expression of the original potentiality of

the Urpflanze:

Nothing has been added in this regulated evolutionary process of the vegetal world that

had not been previously prepared and indicated, so to speak. Neither genus, nor family,

nor class of plants has manifested itself without having become necessary in time.^137

Temkin notes that Unger held that species themselves do not change, but that some

individuals metamorphosed while the old type remained in existence for some time.

(^134) Stresemann 1975, Stroud 2000.
(^135) Quoted in Stresemann 1975, 166.
(^136) Cf. Temkin 1959, 339–342.
(^137) Quoted in Temkin 1959, 340.