Cell: Essay on the History of the Cell!
The word Cell Biology (Cytology) is a Greek word—kytos means hollow vessel or cell, and logous means to discourse, i.e., it deals with the study of cells from morphological, physiological, biochemical, cytochemical, genetical and developmental points of views.
The term cell (Gr., kytos, cell + L., cella, hollow space) was first used by Robert Hooke (1665) to describe his investigations on the “texture of cork by means of magnifying lenses.” Thus Robert Hooke left to us the name of cell (Gr., Cella – a small chamber).
All the living organisms which we see are essentially complex structures made up of numerous coordinated compartments usually called as cells, discrete bodies of protoplasm surrounded by a plasma membrane. Thus, cells are the units of living systems.
Cells show to a considerable extent, an independent existence. The cell is a fundamental structural unit of organisms. The study of these cells was made possible with the help of microscope which was invented in 1590 by Z. Janssen and H. Janssen. Microscope is a Greek word (mikros, small; skopein, to see).
They developed a compound microscope which could magnify an object 30 times to its actual size. Robert Hooke (1635-1703), first curator of the Royal Society of London, discovered that a section of cork is made up of small cavities surrounded by firm walls.
In 1665 in his Micrographia he described the thickened cell walls of dead cells in cork. He used the term ‘cell’ on the basis of his investigations. Grew and Malpighi observed the cavities (utricles or vesicles) of the cellulose wall in different plants.
Later on, A. van Leeuwenhoek (1632-1723) improved microscope lens and observed various unicellular organisms like protozoans, bacteria, sperms, and red blood cells, etc. Leeuwenhoek observed some organization within cells, particularly the nucleus in some erythrocytes. Mirbel, M. in 1809 seems to have the first to state that all plant tissues are composed of cells.
In 1831 Robert Brown observed nucleus in certain plant cells. J.B. Lamarck (1744-1829) stated in 1809 the importance of cell in the living organism. R.J.H. Dutrochet (1776-1847) separated cells of Mimosa by boiling in nitric acid and said, “All organic tissues are actually globular cells, united only by simple adhesive forces.”
Thus all tissues (of animals and plants) are actually cellular tissues which are variously modified. Schwann, T. in 1839, after examining of a variety of plant and animal tissues, concluded that all living organisms are composed of cells.