In the 1660s, Englishman Robert Hooke built the compound microscope he used to observe and then draw 58 of the 60 pictures in his Micrographia. (His other two drawings feature the moon and the stars.) In his youth, Hooke had apprenticed with an artist, and his art skills allowed him to draw the microscopic world in great detail.
The details, like those in this flea drawing, stirred up theological arguments over whether these tiny creatures had been designed. The debate inspired a young Charles Darwin to study that idea.