Cornelius (or Cornelio) Gemma (28 February 1535 – 12 October 1578) was a physician, astronomer and astrologer, and the oldest son of cartographer and instrument-maker Gemma Frisius. He was a professor of medicine at Catholic University of Leuven, and shared in his father's efforts to restore ancient Ptolemaic practice to astrology, drawing on the Tetrabiblos. Another milestone appears in his medical writings: in 1552, Gemma published the first illustration of a human tapeworm. Gemma also has the distinction of being called "the first true orchid hobbyist, in the modern sense."