Cell development Timeline By Caylum Oct 10, 1665 1665 Robert Hook discovered dead tissue Oct 10, 1670 1670 Anton van Leeuwenhoek used his microscrope as lenses to look at pond water Oct 10, 1683 1683 Anton van Leeuwenhoek sent letter to royal about his discoveries first protozoa and bacteria discovered. Oct 10, 1826 1826 Pierre Turpin reported his observations of cell division Oct 10, 1838 1838 Matthias Jakob Schleiden stated first generalized about cells being the building blocks of matter Oct 10, 1839 1839 Theodor Schwann discovered animal tissue is composed of cells Oct 10, 1840 1840 Albrecht von Roelliker discoveres that sperm and eggs are also cells. Oct 10, 1845 1845 Carl Heinrich Braun stated that cells re the basic units of life Oct 10, 1855 1855 Rudolf Virchow discovered that cells are made from other existing cells Oct 10, 1883 1883 Robert Brown discovered Nucleus in plant cells