Heinrich Wilhelm Gottfried Von Waldeyer-Hartz

German anatomist, famous for consolidating the neuron theory of organization of the nervous system and for naming the chromosome. He is also remembered in two macroanatomical structures of the human body which were named after him: Waldeyer's tonsillar ring (the lymphoid tissue ring of the naso- and oropharynx) and Waldeyer's glands (of the eyelids).

Waldeyer's name is sometimes associated in neuroscience with the so-called "neuron theory" and for popularizing the term "neuron" to describe the basic structural unit of the nervous system. Waldeyer used the path-breaking discoveries by neuroanatomists (and later Nobel Prizewinners) Camillo Golgi (1843–1926) and Santiago Ramón y Cajal (1852–1934), who had used the silver nitrate method of staining nerve tissue (Golgi's method) to formulate a short brilliant synthesis, even though he did not contribute with any original observations.

This method allowed them to study in exquisite detail the branching processes of nerve cells (axons anddendrites) and how they seemed to interconnect among themselves, forming chains and neural networks which could explain the physiological mechanisms underlying the phenomena of information transfer between neurons. Waldeyer learned Spanish in order to absorb Cajal's extraordinary 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, Kölliker,Retzius, van Gehuchten and myself, and he invented the fortunate term neuron.