Species

Species and the Birth of Modern Science 83

metaphor of countries adjoining each other.^154 In his early writing, all the territory
is regarded as pretty much lled—as he said, nature does not make jumps—but the
countries are discrete and distinct from one another. In the later work, this strict x-
ism of the rst edition of the Systema Naturae has been modied. All hybrids did
was ll in a rare empty bit of territory in God’s time and plan. The borders were set
by the genera, and all genera arose from a single species created by God.
At the end of the 1750s, says Hagberg,^155 Linnaeus was in a state of perplexity
with respect to species. In 1755, his student Nils Dahlberg published Metamorphoses
plantarum,^156 dealing primarily with the development of plants, but also with mon-
strosities and varieties. Such later hybrids he called the “children of time” in an
anonymous entry in a competition at St. Petersburg in 1759,^157 and also in the Species
plantarum, where he speculated that a species of Achillea (yarrow, or staunchweed),
alpina, might have formed from another, ptarmica, “[a]n locus potuerat ex prae-
cedenti formasse hanc?” (“Could this have been formed from the preceding one
by the environment?”^158 ). Hagberg says, “Linnaeus never succeeded in pin-pointing
his new conception of species. But the old one, that formed the basis of Systema
Naturae, was utterly and irrevocably abandoned.” In fact, reports Lindroth,^159 he
started seeing hybrids everywhere, even where they were not.
Linnaeus also noted that species grew differently according to the conditions of
their locale. Of the genera Salix, Rosa, Rubus, and Hieracium (willows, roses, bram-
bles, and hawkweeds), Linnaeus said that their description was problematic because
of variability (“metamorphosis”) of form in different soils and climates.^160 Linnaeus
also experimented on propagating a hybrid geranium, with success, in 1759; he
believed that maternal inuences of hybrids affected the “medullary substance” and
fructication of plants, but the leaf structure was due to the paternal species.^161 As
time went on, he removed the statement that there were no new species from his
1766 edition of the Systema Naturae, and crossed out the statement natura non facit
saltum from his own copy of his Philosophia Botanica. A full list of Linnaeus’ vari-
ous pronouncements on species can be found in Ramsbottom.
When Linnaeus was working, European trade and exploration were limited.
Linnaeus himself classied around 6000 species of mainly Mediterranean and
northern European plants, and later animals.^162 This was more than had been done
before, but still it was a fraction of what we know today. His students and adher-
ents sent him specimens from around the world, and there was a steady “trade” in

(^154) Philosophia botanica §77 [Linné 1751]:
(^) Nature does not make leaps.
(^) All plants exhibit their contiguities on either side, like territories on a geographical map [translated
in Linné and Freer 2003].
(^155) Hagberg 1952, 199.
(^156) Dahlberg and Linné 1755.
(^157) Hagberg 1952, 201f.
(^158) Volume II, 1266 of the second edition, quoted in Greene 1959, 134.
(^159) Lindroth 1983, 95.
(^160) Ramsbottom 1938, 200f.
(^161) Ramsbottom 1938, 210f.
(^162) Staeu 1971.