Historical Background Of Cell

ROBERT HOOKE (1665):

An English mathematician and physicist developed a microscope and observed thin sections of cork and noticed honey-comb like compartments. He coined them as cells. Term cell was derived from a Latin word cella = a hollow space. He explained his observations in a book namely, Micrographia. He actually observed the rigid cell walls of dead cells.

ANTON VON LEEUWENHOEK (1674):

A Dutch draper, was first to observe living cells and micro-organisms like bacteria, protozoa, spermatozoa, red blood corpuscle etc. He called it animalcules and thus he is also known as animalculist.

• Robert Brown (1831) discovered nucleus and give its name nucleus. He found it in the root cells of orchids.
• Dujardin (1835) reported a semifluid material around the nucleus of muscle cells and named it sarcode.
• J. E. Purkinje (1839) coined the term protoplasm for this jelly-like material, while protoplasm was called “Physical basis of life” by Huxley.
• Malthias J. Schleiden-Botanist (1838) and Theodore Schwann-Zoologist (1839) studied the plant and animal cell and found that every cell is independent in itself and it could perform all living functions. They proposed a most fundamental biological generalisation, called cell theory, which states that :

Cell is the structural and fundamental unit of life.
A cell is a mass of protoplasm containing a nucleus and is bounded by a cell membrane.

New cells are formed de novo (a fresh) analogous to crystal formation.
Viruses are exceptions to cell theory.

• Rudolf Virchow (1855), a German physiologist, proposed Theory of cell Lineage which states “omnis cellula e cellula” which means that cell are formed from the pre-existing cells.

Cell theory was modified into cell principle which states :

Every living organism is cellular. All the cells have similar basic structure with similar kind of cell organelles, so cell is structural unit of life.

Different cells perform similar basic functions of life in a similar manner and even have similar control mechanism, so cell is functional unit of life.

New cells are formed by the growth and division of pre-existing cell.

• Ernst Haeckel (1866) proposed that nucleus stores and transmits the hereditary characters.
• Knoll and Ruska (1932) of Germany designed the electron microscope which was employed to study the ultrastructure (fine structure) of cell and various cell organelles in 1940s.