First depiction of Trichodesmium - 1828

from Hemprich and Ehrenberg's 1828 Symbolae Physicae volume "Botanica" - The plates were first published without any text in 1828. The version shown here is from a re-printed edition published in 1899. Ehrenberg described the organism that gives the Red Sea its occasional color red. The figure A is 'the alga in a glass of water