Swammerdam, Jan (redirected from Swammerdam)

Swammerdam, Jan (yän vä`mərdäm), 1637–80, Dutch naturalist. He was a pioneer in the use of the microscope. Before he turned to religious contemplation his chief interest was the study of invertebrates. He investigated the life histories of frogs and of numerous insects, which he classified on the basis of their metamorphic development. He also made valuable observations on human anatomy and was probably the first to detect red blood cells (1658). A composite collection of his descriptions and of his accurate and exquisitely executed drawings was published posthumously (2 vol., 1737–38) and appeared in English as The Book of Nature (1758). He was an early and influential proponent of the theory of evolution, in opposition to the current belief in spontaneous generation.

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Swammerdam, Jan

(born Feb. 12, 1637, Amsterdam, Neth.—died Feb. 15, 1680, Amsterdam) Dutch naturalist. An adept microscopist, in 1658 he became the first person to observe and describe red blood cells. In his General History of Insects he accurately described and illustrated the life histories and anatomy of many insect species and classified insects into four major divisions, three of which have been more or less retained in modern classification. He studied tadpole and adult frog anatomy and described the ovarian follicles of mammals. His improved techniques for injecting wax and dyes into cadavers had important consequences for the study of human anatomy. He showed that muscles alter in shape but not in size during contraction.