Max Johann Sigismund Schultze

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Max Johann Sigismund Schultze


German Zoologist and Cytologist

Max Johann Sigismund Schultze was a German zoologist and cytologist. Zoology is a part of biology that focuses its study on animal life and the animal kingdom in general. Cytology is the study of cells and how cells function.

Born in 1825 in Freiburg, Germany, Max Schultze attended school at the University of Greifswald in Germany, from which he graduated in 1849. He also studied at the University of Berlin. In 1859, following several years of teaching anatomy in Halle, he began teaching anatomy at the University of Bonn. In 1872 the University of Bonn offered Schultze a chair, a permanent position, and so he became the director of the Anatomical Institute.

Schultze's primary research focus was on a part of the cell he called protoplasm, which essentially includes all the material inside the cell membrane. As a cytologist Schultze's best-known work pertained to unicellular organisms. In 1861 he was able to establish that cells of all organisms contain protoplasm. Today a more common term for protoplasm is cytoplasm.

Max Schultze's talents in the science arena were extensive. He was also a histologist, which is a part of biology that focuses on the structure and composition of animal and plant tissues as they pertain specifically to their functions. As a histologist he discovered and developed the stain used to aid in microscope viewing. The stain is called osmic acid and has the ability to allow the viewer to see the fine details of cell. His best use of this stain was to enhance the viewing of nervous tissues in the basilar membrane of the ear. His scientific writings covered other sensory organs: the internal ear (1858), the nose (1863), and the retina of the eye (1866), muscles, and nerve endings.

During his life Max Schultze was also able to show that the retinas of birds have rods and cones, two different sensory nerve endings that have separate functions. Birds and humans are the only organisms to have rods and cones. Light first passes through the liquid in the eyeball. The light then penetrates through several additional layers of cells before reaching the rods and cones, which are light sensitive. A rod is a specialized photoreceptor cell and is sensitive to light; however it is not sensitive to color. The rod responds in dim light is used primarily in peripheral vision. A cone is a color-sensitive photoreceptor cell and is associated with visual acuity. In 1866 Schultze proposed the duplicity theory of vision, which is that cones and rods are two different cells in the eye. His theory was a forerunner of modern theories of vision.

Max Schultze died in Bonn, Germany, in 1874. It is interesting to consider how Schultze was able to conduct his research. During his lifetime it was against the law to perform dissection on humans, and thus all of his research was performed on animals. His ability to directly correlate humans and animals was amazing. His observations have held up remarkably well in today's understanding of the senses.