The cell, the unit of life

An old black-and-white engraving shows, in two discs, greatly magnified slices of cork made up of small aligned compartments, and below them a plant sprig. — Two greatly magnified slices of cork and a sprig: engraving from Robert Hooke’s book Micrographia (1665), plate 11. Robert Hooke (engraving from Micrographia); digitisation Wellcome Collection, CC BY 4.0, source

In 1951, cells were taken from Henrietta Lacks and then used for research, without either her or her family being consulted.

This site tells the stories of people whose work was attributed to others.

This page raises another kind of question, which must be carefully distinguished: it is not a question of merit, but a question of permission.

Two questions that look alike

The first: to whom does the credit for a piece of work belong?
This is the question raised by our entries on Lise Meitner, Marie Tharp, Mary Anning or Onesimus. Someone made a major advance, and another person signed it, was cited for it or went down in history in their place.

The second: who had the right to decide?
It is not about merit or intellectual authorship. It is about consent — that is, having been fully informed, having understood, and having given one’s express agreement.

These two questions look alike, but they are not of the same nature: the first concerns a work; the second concerns a person.

Confusing them leads to the wrong kind of redress. When it is a matter of credit — Meitner, Tharp, Anning — redress consists in restoring authorship of the work, citing the person, writing them into the history of science. When it is a matter of consent, naming the person redresses nothing: she was not seeking to publish or to contribute; her body was used without her knowledge. What she was owed was not recognition after the fact, but a request beforehand.

Credit can be restored. Consent, however, cannot be made up for.

During the twentieth century, cells taken from patients without their knowledge or without prior information were cultured, multiplied and distributed to laboratories around the world, serving as the basis for enormous biomedical advances.

In several emblematic cases — such as that of the cells of Henrietta Lacks (HeLa cells) — neither the person nor her family had been consulted.¹

The legal framework of the time: in 1951, no American federal rule governed the use of patients’ cells in research; the Nuremberg Code dates from 1947, the Declaration of Helsinki from 1964.
What has changed: the Declaration of Helsinki, revised in 2024, requires free and informed consent to collect and store biological material for research; otherwise, an ethics committee must authorise it.²

What the 2013 agreement says, and what it admits

In 2013, sixty-two years after the sample was taken in 1951, an agreement was reached between the American public research body and the Lacks family.³

It created a committee of six people, including two family members, tasked with reviewing requests for access to the genetic data derived from these cells. The body’s director states that he met the family three times in four months before reaching it.⁴

What makes this agreement interesting is what the body itself acknowledges.

Through its deputy director, it declares itself fully aware that the data already published could be pieced together, and that any sufficiently equipped laboratory could obtain the entire sequence without any funding from it.⁵

The agreement therefore prevents nothing technically. It binds only those who agree to abide by it.

Sixty-two years on, what can be redressed is therefore not access to the cells, but the place given to the family in decisions. The missing consent cannot be made up for; it is only possible to stop deciding without them.

Editorial treatment: A full analysis of the legal proceedings and of the recent agreements reached by the rights holders is the subject of a dedicated update, written with respect for the people concerned and their families.

The man who named the cell thought he was naming holes

In 1665, the English scientist Robert Hooke published Micrographia, a collection of observations made with a microscope. Examining a thin slice of cork, he saw a honeycomb-like structure made up of small irregular cavities bounded by walls.⁶

He named them “cells” — a word that then referred to the small rooms of monasteries, but also the compartments of a honeycomb. And it was indeed to a honeycomb that he compared what he saw.⁷

He grasped the significance of his observation, and wrote it down: these were, he said, the first microscopic pores he had ever seen, and perhaps the first ever seen — he had found no author before him who mentioned them.⁸

The initial error: cork is dead plant tissue. What Hooke was observing was not the living contents, but the empty wall left behind by the cells that had disappeared. He named holes.

What must nevertheless be acknowledged

It is often repeated that he never saw a living cell. That is not accurate, and he said so himself in the same observation.

Examining plants while still green, he stated that with the microscope he had very clearly made out these same cells or pores, this time filled with juices.⁹

So he did perceive the difference between a full cell and an empty cell. What he lacked was not the observation, but the idea that this small room was the unit of which all living things are made. Seeing is not understanding — that is precisely the subject of the rest of this page.

The trilogy of knowledge

Step	Who	What was done
1. Naming	Robert Hooke (1665)	Describes a honeycomb-like structure in dead cork and gives it its name. He also observes, in green plants, these same cells filled with juices.
2. Observing	Antoni van Leeuwenhoek	Is the first to see living micro-organisms, with a single lens magnifying more than 250 times.
3. Understanding	Schleiden and Schwann (1839)	State that the cell is the fundamental unit of life.

Antoni van Leeuwenhoek: seeing without naming

A few years later, in the Netherlands, Antoni van Leeuwenhoek designed microscopes with a single, highly convex lens, reducing optical aberrations. With an unprecedented magnification of more than 250 times, he observed microscopic life for the first time:¹⁰

1674: Discovery of protozoa and single-celled organisms.
1676: First observation of bacteria.
1677: Observation of spermatozoa.¹¹

Lacking the modern theoretical vocabulary, he simply called them, in Dutch, “diertgens” — little beasts.¹²

One misconception deserves to be pointed out. It is repeated everywhere that he named them “animalcules”. This word is not his: it is not even Dutch. It was his translator in London who introduced it, by Latinising his vocabulary.¹³

Leeuwenhoek described what he saw in everyone’s words; he has been credited with those of a scholar.

When a sentence crosses into another language, it does not only lose words: it sometimes changes tone.

Discovering, naming, understanding

The history of the cell illustrates a general principle: discovering, naming and understanding are three distinct acts, often carried out by different people at different times.

Hooke named a structure, first seen empty in dead material.
Leeuwenhoek observed living things without being able to categorise them.
It was not until 1839 (with Matthias Schleiden and Theodor Schwann) that cell theory established that every living being is made up of cells.¹⁴

Words keep the memory of the concepts of their time: the term “cell” continues to designate the unit of life, even though it was chosen with the image of empty cavities in mind.

What a cell is

All living organisms are made up of cells, whether they are unicellular (bacteria, yeasts) or multicellular (plants, animals, fungi). This is what is called the unity of life.

Contemporary molecular and cellular analyses have made it possible to redefine phylogeny: the comparison of protein sequences shows, for example, that fungi are closer to animals than to plants.¹⁵

Biological relationships are not understood by observing the outward appearance of living beings, but by analysing their internal structure.

Note 1

Doctors extracted cells from her tumor sample without her knowledge or consent for further research. […] “We were often in the dark regarding the use of her cells, we usually found out after the fact, through the media,” said David Lacks.

Haughey, Marie, “NIH–Lacks Family Partnership Gives Henrietta Lacks’ Descendants a Seat at the Table”, The Poster, NCI at Frederick (National Cancer Institute), 28 September 2017