Linnaeus on species

Since Linnaeus' birthday is tomorrow, my time, and I stuffed up the last post, here's another little treat for you:

Carl Linnaeus (1707–1770, from 1761 Carl von Linné, or Carolus Linnaeus)

There are many myths about Linnaeus that are due to the properties, real or imagined, of the system named after him (Cain 1994; Koerner 1999; Larson 1968; Winsor 2006). In fact the so-called "Natural System" as it came to be known, was on Linnaeus' own view an artificial one (Cain 1995), and it did not spring forth fully formed from his brow, no matter how much he saw himself as a "second Adam". His view on species was initially fairly standard, based on John Ray's previous definition (perhaps not consciously), and which included fixity. But not, it seems, because of essentialism, but piety.

Linnaeus seems to have defined each species diagnostically, not materially. That is to say, given that species are fixed from the creation, what are the marks of species so we can recognise them? However, he famously discovered what he thought was a novel hybrid species, and so towards the end of his life, began to backpedal the extreme fixity of the earlier writings, calling one such apparent novel species a "daughter of time" (Gustafsson 1979). This was widely known among the botanical community, and was widely accepted. For him, constancy (not essence) of generation was the key to species.

Below the fold are his definitions of "species", or rather, his comments about species. So far as I know, he never actually defined the term.

There are as many species as the Infinite Being produced diverse forms in the beginning. [Species tot sunt diversae quot diversas formas ab initio creavit infinitum Ens, Fundamenta botanica No. 157, 1736 (quoted in Ramsbottom 1938:196)]

We reckon as many species as there were diverse forms created in the beginning. [Species tot numeramus, quot diversae formae in principio sunt creatae, Philosophia Botanica, 1751 (loc. cit.)]

Species are as many as there were diverse [and constant*] forms produced by the Infinite Being; which forms according to the appointed laws of generation, produced more individuals but always like themselves. Therefore there are as many species as there are different forms or structures occurring today. [Species tot sunt, quot diversas [& constantes*] formas ab initio producit Infinitum Ens; quae formae, secundum generationis inditas leges, produxere plures, at sibi semper similes. Ergo species tot sunt, quot diversae formae s. structurea hodienum occurrant. Classes Plantarum, 1738 (loc.cit.). *Added in 1764, see Genera Plantarum I: ¶5]

The principle being accepted that all species of one genus have arisen from one mother through different fathers, it must be assumed:

1. That in the beginning the Creator created each natural order only with one plant with reproductive power.

2. That by their various mixings different plants have arisen which belong to the mother's natural order as they are similar to the mother with regard to their fructifications, and are, as it were, species of the order, i.e., genera.

3. We may assume that plants have arisen within the orders, i.e. by genera of one order, may mix with each other. In this way there will arise species that should be referred to the mother's genus as her daughters. [Pralectiones (Lectures, 1744), quoted in Larson, (1967:317)]

We say there are as many genera as there are similarly constituted fructifications of different natural species. [Genera tot dicimus, quot similes contructae fructifications proferunt diversae Species naturales. Fundamenta Botanica 1736, No 159 (quoted in Ramsbottom 1938:197)]

Every genus is natural, created as such in the beginning, hence not to be rashly split up or stuck together by whim or according to anyone's theory. [Genus omne est naturale, in primordio tale creatum, hinc pro libitu & secundem cujuscimque theoriam non proterve discindendum aut conglutinandum. Systema naturae, 1735, (quoted in Ramsbottom 1938:197)]

Species are most constant, since their generation is a true continuation. [Species constantissimae sunt, cum earum generatio est vera continuatio. Systema naturae, 1735 (quoted in Ramsbottom 1938:197)]

There are as many varieties as there are different plants, produced from the seed of the same species. [Varietates tot sunt, quot differentes plantae ex ejusdem speciei semine sunt productae. Philosophia Botanica 1751(quoted in Ramsbottom 1938:199)]

Is the plant [Thalictrum lucidum] sufficiently distinct from T. flavum? It seems to me a daughter of time. [Planta, an satis distincta, a T. flavo? Videtur temporis filia. Species plantarum 1753 (quoted in Ramsbottom 1938:201)]

References

Cain, A. J. 1995. Linnaeus's natural and artificial arrangements of plants. Botanical Journal of the Linnean Society 117 (2):73.

Cain, Arthur J. 1994. Numerus, figura, proportio, situs: Linnaeus's definitory attributes. Archives of Natural History 21:17-36.

Gustafsson, Ö. 1979. Linnaeus' Peloria: The history of a monster. TAG Theoretical and Applied Genetics 54 (6):241-248.

Koerner, Lisbet. 1999. Linnaeus: nature and nation. Cambridge, Mass: Harvard University Press.

Larson, James L. 1967. Linnaeus and the Natural Method. Isis 58 (3):304-320.

———. 1968. The Species Concept of Linnaeus. Isis 59 (3):291-299.

Ramsbottom, John. 1938. Linnaeus and the species concept. Proceedings of the Linnean Society of London 150 (192-220).

Winsor, Mary P. 2006. Linnaeus' biology was not essentialist. Annals of the Missouri Botanical Garden 93 (1):2–7.