Animalcule

Animalcule(Latinfor 'little animal'; fromanimaland-culum) is anarchaic termformicroscopicorganismsthat includedbacteria,protozoans,and very smallanimals.The word was invented by 17th-century Dutch scientistAntonie van Leeuwenhoekto refer to themicroorganismshe observed inrainwater.

Some better-known types of animalcule include:

• Actinophrys,and otherheliozoa,termed sun animalcules.
• Amoeba,termedProteusanimalcules.
• Noctiluca scintillans,commonly termed the sea sparkles.
• Paramecium,termed slipper animalcules.
• Rotifers,termed wheel animalcules.
• Stentor,termed trumpet animalcules.
• Vorticella,and otherperitrichs,termed bell animalcules.

The concept seems to have been proposed at least as early as about 30 BC, as evidenced by this translation fromMarcus Varro'sRerum Rusticarum Libri Tres:

Note also if there be any swampy ground, both for the reasons given above, and because certain minute animals, invisible to the eye, breed there, and, borne by the air, reach the inside of the body by way of the mouth and nose, and cause diseases which are difficult to be rid of.

The term was also used during the 17th century byHenry Oldenburg,the first Secretary of theRoyal Societyand founding editor ofPhilosophical Transactions,to translate the Dutch words used by van Leeuwenhoek to describe microorganisms that he discovered.

In Gilbert and Sullivan'sThe Pirates of Penzance,the word appears in adjectival form in the 'Major-General's Song', in which Major-General Stanley sings, 'I know thescientific namesof beings animalculous...'

The term continued to be current at least as late as 1879.

A 1795 illustration of van Leeuwenhoek's animalcules by an unknown artist.

A 1795 illustration of van Leeuwenhoek's animalcules by an unknown artist

See also

• Caminalcule
• Infusoria
• Van Leeuwenhoek's microscopic discovery of microbial life(microorganisms)