Ernest Just

 Ernest Everett Just (August 14, 1883 – October 27, 1941) was a pioneering African American biologist,
academic and science writer. Just's primary legacy is his recognition of the fundamental role of the cell surface in the development of organisms.

 Source: vintage black photos | tumblr
( restlessandcr8ive)

Sir Alexander Fleming

Sir Alexander Fleming FRSE, FRS, FRCS(Eng) (6 August 1881 – 11 March 1955) was a Scottish biologist and pharmacologist.
On Sept. 28, 1928 Sir Alexander Fleming notices a bacteria-killing mold growing in his laboratory, discovering what later became known as penicillin…
 Photo of Fleming ‘working’ - by Alfred Eisenstaedt, London

 Source: Ordinary Finds