Schultze was born at Freiberg in Germany. He was educated at the University of Griefswald, where his father was professor of anatomy, and the University of Berlin. After a brief period on the staff of the University of Halle he moved in 1859 to Bonn where he served as professor of zoology until his sudden death in 1874 from a perforated ulcer.

In 1861 Schultze, who had worked on the cellular structure of a wide variety of animals, published a famous paper in which he emphasized the role of protoplasm in the workings of the cell. Cells, he argued, were ‘nucleated protoplasm’ or ‘the physical basis of life’, the protoplasm and not the cell wall being the important constituent. This he illustrated by pointing out that some cells, for example those of the embryo, do not have bounding membranes.

In 1866 Schultze went on to formulate the so-called duplicity theory of vision. He had noticed that in diurnal birds the retina consisted mainly of cones but nocturnal birds possessed a retina with an abundance of rods. This led him to propose that cones must respond to colored light while rods should be more sensitive to black and white.