Matthias Schleiden (1804 – 1881)

The botanist (botany is the study of plants) Matthias Jakob Schleiden was born in Hamburg, Germany on April 5th 1804. Schleiden studied law at Heidelberg and practiced as a legal advocate in Hamburg, Germany until 1831. Having had little success in this career, he began studying botany and medicine at Gottingen and Berlin, and in 1839 graduated from Jena, where he was appointed extraordinary professor of botany from 1839-1862. In 1863, Schleiden was called to Dorpat, Estonia, but resigned the following year and returned to Germany, where he lived as a private teacher.

As a professor at Jena and Dorpat, Schleiden began investigating of the nature of plants, working under Johannes Müller. Unlike his contemporaries who simply classified plants according to their physical characteristics, Schleiden studied them with a microscope. As a result, in the year 1838, Schleiden was the first person to recognize the importance of cells in plants, first discovered by Robert Hooke in 1655, and wondered if the nucleus had something to do with development. Schleiden observed that all plants seemed to be composed of cells, and he proposed that these cells were the most basic unit of life in the plants. He proposed that plant growth took place by the generation of new cells, which, he argued, would propagate or ‘crystallize’ from buds on the nucleus of old cells. Although later work would show his proposal regarding the budding of the cell nucleus was not completely correct, his theories that the cell was the common structural unit to all plants, and that growth occurred by the addition of new cells, attracted significant attention. A year after Schleiden published his cellular theory of plants in Beiträge zur Phytogenesis (Contributions of Phytogenesis) in 1838, his friend and collaborator Theodor Schwann made similar observations in animals. Together, Schleiden and Schwann unified botany and zoology under a common theory that the cell is the basic structural unit of living organisms, both animal and plant. As a result, the two are considered the founders of modern cell theory.     

Schleiden wrote a number of books and papers over the course of his life including Introduction to Scientific Botany (1842-1843), Manual of Botany Doctor-Pharmaceutics (1852-1857) and The Plants and their Life (1864). On June 23, 1881, Matthias Schleiden died at Frankfort-on-Main.