Animalcule ('little animal', from Latin animal + the diminutive suffix -culum) is an old term for a microscopic organisms that included bacteria, protozoans, and very small animals. The word was invented by  Antonie van Leeuwenhoek to refer to the microorganisms he observed in rainwater. The term was also used during the 17th century by Henry Oldenburg, the first Secretary of the Royal Society and founding editor of Philosophical Transactions, to translate the Dutch words used by Anton van Leeuwenhoek to describe microorganisms that he discovered.
Animalcule ('little animal', from Latin animal + the diminutive suffix -culum) is an old term for microscopic organisms that included bacteria, protozoans, and very small animals. The word was invented by 17th-century Dutch scientist Antonie van Leeuwenhoek to refer to the microorganisms he observed in rainwater. The term was also used during the 17th century by Henry Oldenburg, the first Secretary of the Royal Society and founding editor of Philosophical Transactions, to translate the Dutch words used by van Leeuwenhoek to describe microorganisms that he discovered.
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17th-century Dutch scientist
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Anton