- Quinarian system
The Quinarian system was a method of zoological classification which had a brief period of popularity in the mid 19th century, especially among British naturalists. It was largely developed by the entomologist W. S. MacLeay in 1819. The system was followed by
Nicholas Aylward Vigors andWilliam John Swainson . Swainson's work on ornithology gave wide publicity to the idea.O’Hara, Robert J. 1988. Diagrammatic classifications of birds, 1819–1901: views of the natural system in 19th-century British ornithology. Pp. 2746–2759 in: Acta XIX Congressus Internationalis Ornithologici (H. Ouellet, ed.). Ottawa: National Museum of Natural Sciences. [http://rjohara.net/cv/1988-ioc Full text] ] Quinarianism gets its name from the emphasis on the number five: it proposed that all taxa are divisible into five subgroups, and if only four subgroups are known, quinarians believed that a missing subgroup remained to be found.Presumably this arose as a chance observation of some accidental analogies between different groups, but it was erected into a guiding principle by the quinarians. It became increasingly elaborate, proposing that each group of five classes could be arranged in a circle, with those closer together having greater affinities. Typically they were depicted with relatively advanced groups at the top, and degenerate forms towards the bottom. Each circle could touch or overlap with adjacent circles (a phenomenon called 'osculation'). Another aspect of the system was the identification of "analogies" across groups: [O’Hara, Robert J. 1991. Representations of the natural system in the nineteenth century. Biology and Philosophy. 6(2):255–274. [http://rjohara.net/cv/1991-bp.html Text] ]Quinarianism was not widely popular outside the United Kingdom; it had become more or less unfashionable by the 1840s, during which time more complex "maps" were made by
Hugh Edwin Strickland andAlfred Russell Wallace . Strickland and others specifically rejected the concept of "analogy". [Strickland, H.E. (1841) On the true method of discovering the natural system in zoology and botany. Annals and Magazine of Natural History 6:184–194 [http://books.google.com/books?id=5KMEAAAAYAAJ&pg=RA2-PA408&lpg=RA2-PA408&dq=on+the+true+method+of+discovering+the+natural+system+in+zoology+and+botany&source=web&ots=x5UXkVxd5e&sig=sj_t4WPWRo4xJVSp8mAf4LkxIXA Full Text] .] These systems were eventually discarded in favour of principles of classification based on evolutionary relationship. [Pachen, Alec L. (1992)Classification, Evolution, and the Nature of Biology. Cambridge University Press.]References
Wikimedia Foundation. 2010.
