How Did Schleiden and Schwann Discover the Cell Theory?


Vincent White

In the field of biology, the cell theory is considered one of the most fundamental concepts, which states that all living organisms are composed of cells. The development of this theory is attributed to two German scientists, Matthias Schleiden and Theodor Schwann. In the mid-19th century, they worked together to investigate the nature of living things and made some groundbreaking discoveries that laid the foundation for modern cell biology.

The Discovery of Schleiden

Matthias Schleiden was a botanist who had a keen interest in studying plant tissues. In 1838, he published a paper titled “Contributions to Phytogenesis,” where he proposed that every part of a plant is composed of cells or derivatives of cells.

He observed that every plant tissue he examined under a microscope consisted of elongated structures with walls that formed closed cavities. From this observation, he concluded that these cavities were cells and suggested that they were the basic units of plants.

The Discovery of Schwann

Around the same time, Theodor Schwann was a physiologist who was studying animal tissues. He observed similar structures in animal tissues under a microscope and came to similar conclusions as Schleiden did.

In 1839, Schwann published his findings in a paper titled “Microscopical Researches into the Accordance in the Structure and Growth of Animals and Plants.” He proposed that animals were also composed of cells and suggested that cells were not only structural units but also functional units.

The Cell Theory

Schleiden and Schwann began to correspond with each other about their respective findings, which led to their collaboration on developing what is now known as the cell theory. In 1846, they jointly published “Theories on the Structure of Plants and Animals,” which presented their combined work on cells as basic units in all living organisms. The cell theory proposed that:

  • All living organisms are composed of one or more cells.
  • The cell is the basic unit of life and the structural and functional unit of all living things.
  • All cells arise from pre-existing cells by division.

This theory was a major breakthrough in biology, and it laid the foundation for modern cell biology. It helped to explain how living organisms function and how they are related to each other. The cell theory also provided new avenues for research, leading to new discoveries in fields such as genetics, microbiology, and immunology.


In conclusion, Schleiden and Schwann’s discovery of the cell theory was a significant moment in the history of biology. Their work paved the way for modern cell biology and helped us understand how living organisms function at a fundamental level. Their use of microscopes to observe plant and animal tissues was revolutionary at the time, and their findings continue to shape our understanding of life today.