Heinrich Wilhelm Gottfried von Waldeyer-Hartz (6 October 1836 – 23 January 1921) was a German

anatomist Anatomy () is the branch of morphology concerned with the study of the internal structure of organisms and their parts. Anatomy is a branch of natural science that deals with the structural organization of living things. It is an old scien ...

, known for summarizing neuron theory and for naming the

chromosome A chromosome is a package of DNA containing part or all of the genetic material of an organism. In most chromosomes, the very long thin DNA fibers are coated with nucleosome-forming packaging proteins; in eukaryotic cells, the most import ...

. He is also remembered by anatomical structures of the human body which were named after him: Waldeyer's tonsillar ring (the lymphoid tissue ring of the naso- and

oropharynx The pharynx (: pharynges) is the part of the throat behind the mouth and nasal cavity, and above the esophagus and trachea (the tubes going down to the stomach and the lungs respectively). It is found in vertebrates and invertebrates, though its ...

) and Waldeyer's glands (of the eyelids).

Contribution to neuron theory

Waldeyer's name is associated in

neuroscience Neuroscience is the scientific study of the nervous system (the brain, spinal cord, and peripheral nervous system), its functions, and its disorders. It is a multidisciplinary science that combines physiology, anatomy, molecular biology, ...

with the " neuron theory", and for coining the term "

neuron A neuron (American English), neurone (British English), or nerve cell, is an membrane potential#Cell excitability, excitable cell (biology), cell that fires electric signals called action potentials across a neural network (biology), neural net ...

" to describe the basic structural unit of the

nervous system In biology, the nervous system is the complex system, highly complex part of an animal that coordinates its behavior, actions and sense, sensory information by transmitting action potential, signals to and from different parts of its body. Th ...

. Waldeyer synthesized the discoveries by neuroanatomists (and later

Nobel Prize The Nobel Prizes ( ; ; ) are awards administered by the Nobel Foundation and granted in accordance with the principle of "for the greatest benefit to humankind". The prizes were first awarded in 1901, marking the fifth anniversary of Alfred N ...

winners)

Camillo Golgi Camillo Golgi (; 7 July 184321 January 1926) was an Italian biologist and pathologist known for his works on the central nervous system. He studied medicine at the University of Pavia (where he later spent most of his professional career) bet ...

(1843–1926) and Santiago Ramón y Cajal (1852–1934), who had used the

silver nitrate Silver nitrate is an inorganic compound with chemical formula . It is a versatile precursor to many other silver compounds, such as those used in photography. It is far less sensitive to light than the halides. It was once called ''lunar causti ...

method of staining nerve tissue ( Golgi's method), to formulate widely cited reviews of the theory. Waldeyer learned Spanish in order to absorb Cajal's detailed studies using Golgi's method and became his friend, mentor and promoter in the German-dominated field of microscopic anatomy. The theory was published in a series of papers in the main medical journal of Germany, '' Deutsche Medizinische Wochenschrift'', which became extremely influential. However, as Cajal points out, though Waldeyer "supported the theory with the prestige of his authority, he did not contribute a single personal observation. He limited himself to a short brilliant exposition of the objective proofs, adduced by

His His or HIS may refer to: Computing * Hightech Information System, a Hong Kong graphics card company * Honeywell Information Systems * Hybrid intelligent system * Microsoft Host Integration Server Education * Hangzhou International School, ...

, Kölliker, Retzius, van Gehuchten and myself, and he invented the fortunate term ''neuron''."

Cytology and embryology

Waldeyer also studied the

basophilic Basophilic is a technical term used by pathologists. It describes the appearance of cells, tissues and cellular structures as seen through the microscope after a histological section has been stained with a basic dye. The most common such dye ...

stained filaments which had been found to be the main constituents of

chromatin Chromatin is a complex of DNA and protein found in eukaryote, eukaryotic cells. The primary function is to package long DNA molecules into more compact, denser structures. This prevents the strands from becoming tangled and also plays important r ...

, the material inside the

cell nucleus The cell nucleus (; : nuclei) is a membrane-bound organelle found in eukaryote, eukaryotic cell (biology), cells. Eukaryotic cells usually have a single nucleus, but a few cell types, such as mammalian red blood cells, have #Anucleated_cells, ...

, by his colleague of

Kiel Kiel ( ; ) is the capital and most populous city in the northern Germany, German state of Schleswig-Holstein. With a population of around 250,000, it is Germany's largest city on the Baltic Sea. It is located on the Kieler Förde inlet of the Ba ...

, Walther Flemming (1843–1905). Although its significance for genetics and for cell biology was still to be discovered, these filaments were known to be involved in the phenomenon of

cell division Cell division is the process by which a parent cell (biology), cell divides into two daughter cells. Cell division usually occurs as part of a larger cell cycle in which the cell grows and replicates its chromosome(s) before dividing. In eukar ...

discovered by Flemming, named

mitosis Mitosis () is a part of the cell cycle in eukaryote, eukaryotic cells in which replicated chromosomes are separated into two new Cell nucleus, nuclei. Cell division by mitosis is an equational division which gives rise to genetically identic ...

, as well as in

meiosis Meiosis () is a special type of cell division of germ cells in sexually-reproducing organisms that produces the gametes, the sperm or egg cells. It involves two rounds of division that ultimately result in four cells, each with only one c ...

. He coined in 1888 the term "chromosome" to describe them. Among his many other anatomical and embryological studies, Waldeyer became known for his pioneering research on the development of

teeth A tooth (: teeth) is a hard, calcified structure found in the jaws (or mouths) of many vertebrates and used to break down food. Some animals, particularly carnivores and omnivores, also use teeth to help with capturing or wounding prey, tear ...

and

hair Hair is a protein filament that grows from follicles found in the dermis. Hair is one of the defining characteristics of mammals. The human body, apart from areas of glabrous skin, is covered in follicles which produce thick terminal and ...

, many of the terms he invented are still in use today. He also published the first embryological, anatomical and functional studies about the naso-oro-pharyngeal lymphatic tissue, which received his name. In 1904, he was elected as a member to the

American Philosophical Society The American Philosophical Society (APS) is an American scholarly organization and learned society founded in 1743 in Philadelphia that promotes knowledge in the humanities and natural sciences through research, professional meetings, publicat ...

Bibliography

* Über Karyokinese und ihre Beziehungen zu den Befruchtungsvorgängen. ''Archiv für mikroskopische Anatomie und Entwicklungsmechanik'', 1888, 32: 1–122. Paper about mitosis and chromosomes. * Ueber einige neuere Forschungen im Gebiete der Anatomie des Centralnervensystems. ''Deutsche medicinische Wochenschrift'', Berlin, 1891: 17: 1213–1218, 1244–1246, 1287–1289, 1331–1332, 1350–1356. (About some new researches in the field of anatomy of the central nervous system). His most famous statement and summary of the neuron theory. * W. von Waldeyer-Hartz: ''Lebenserinnerungen''. Bonn, 1920; 2nd edition; Bonn, 1921; 3rd edition, 1922. His memoirs.

References and notes

External links

Heinrich Wilhelm Gottfried Waldeyer-Hartz
WhoNamedIt.
Short biography and bibliography
in the Virtual Laboratory of the Max Planck Institute for the History of Science {{DEFAULTSORT:Waldeyer 1836 births 1921 deaths German anatomists German neuroscientists Members of the Prussian House of Lords Scientists from the Duchy of Brunswick History of neuroscience Corresponding members of the Saint Petersburg Academy of Sciences Foreign associates of the National Academy of Sciences Academic staff of the University of Strasbourg Members of the American Philosophical Society Members of the Royal Society of Sciences in Uppsala Recipients of the Cothenius Medal