Christian Gottfried Ehrenberg, German naturalist, mid-late 19th century.

GERMANY - JULY 11: Carte de visite photograph by Wilhelm Fechner of Ehrenberg (1795-1876). He was a professor at Berlin from 1839 and was a friend of the famous scientist and explorer Alexander von Humboldt. Ehrenberg travelled in Egypt, Syria, Arabia and Central Asia, collecting thousands of specimens from which in turn he described thousands of new species. His research on microscopic organisms led to the founding of Micropaleontology, a new branch of the sciences. Ehrenberg also discovered that phosphorescence in the sea is caused by living organisms. (Photo by SSPL/Getty Images)