Heinrich Wilhelm Gottfried von Waldeyer-Hartz (6 October 1836 – 23 January 1921) was a German anatomist, known for summarizing neuron theory[1] and for naming the chromosome.

[1] 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.

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.

"[6] Waldeyer also studied the basophilic stained filaments which had been found to be the main constituents of chromatin, the material inside the cell nucleus, by his colleague of Kiel, Walther Flemming (1843–1905).