Robert Tuttle Morris, also known as Bob Morris (14 May 1857, Seymour, Conn- 10 January 1945, Stamford) was an American surgeon and writer. He married Aimee Reynand Mazergue on 4 June 1898.
His father was a lawyer, probate judge and Governor of Connecticut, and his mother Eugenia was an author. He went to school at Hopkins Grammar School in New Haven, before studying biology at Cornell University from 1875-1879. He graduated from the College of Physicians and Surgeons of New York in 1882, then spent a two year internship at Bellevue Hospital. He then visited Europe, meeting Lister in London in 1884, and was one of the first to introduce Lister's teachings about surgical hygiene to the United States.
He settled at first in Albany, the moved to New York and began teaching at the New York Post-Graduate Medical School in 1889, becoming a professor of surgery in 1898, a position he held until 1917.
He was an accomplished surgeon who performed the first human ovarian grafting in 1895. He adopted early intervention for appendicitis in 1890, and wrote about its treatment.
He is known for several aphorisms, including "The last living thing on earth will most certainly be a microbe." He told the Cornell Club that World War One was like a Darwinian struggle, but that countries would better recognise the importance of mutual dependence, and he believed that races and hybrids of them depended on "protoplasm" for their success. He also argued that many great writers wrote how they did due to the influence of bacterial toxins on their brains.