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the invention of the microscope at the beginning of the seventeenth
century made it possible to take a first glimpse at the previously invisible world of microscopic life -
Robert Hooke (1635– 1702), was a English physicist who was also a distinguished microscopist. In 1665 Hooke published Micrographia, the first important work devoted to microscopical observation and he coined the term ‘‘cells” -
Botanist Matthias Jakob Schleiden (1804–1881) suggested that every structural element of plants is composed of cells or their products
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Zoologist Theodor Schwann (1810–1882) stated that “the elementary parts of all tissues are formed of cells” and that “there is one universal principle of development for the elementary parts of organisms... and this principle is in the formation of cells”
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Scottish botanist Robert Brown (1773– 1858) was the first to recognize the nucleus (a term that he introduced) as an essential constituent of living cells -
1839, which was when the cell theory was officially formulated -
In the 1850s by Robert Remak (1815–1865), Rudolf Virchow (1821–1902) and Albert Kölliker (1817–1905) who showed that cells are formed through scission of pre-existing cell. Virchow’s aphorism omnis cellula e cellula (every cell from a pre-existing cell) thus became the basis of the theory of tissue formation -
Oil immersion lens were introduced in 1870. The development of the microtome technique and the use of new fixing methods and dyes greatly improved microscopy. Towards the end of the nineteenth century, the principal organelles that are now considered to be parts of the cell were identified -
Walther Flemming (1843–1905), who also introduced the term ‘‘mitosis’’ in 1882 and gave a superb description of its various processes. Flemming observed the longitudinal splitting of salamander chromosomes (a term introduced only in 1888 by Wilhelm Waldeyer, 1836–1921) during metaphase and established that each half chromosome moves to the opposite pole of the mitotic nucleus -
The mitochondria was observed by several authors and named by Carl Benda (1857–1933) in 1898