Giovanni Battista Grassi (27 March 1854 – 4 May 1925) was an Italian physician and zoologist, best known for his pioneering works on parasitology, especially on malariology. He was Professor of Comparative Zoology at the University of Catania from 1883, and Professor of Comparative Anatomy at Sapienza University of Rome from 1895 until his death. His scientific contributions covered embryological development of honey bees, on helminth parasites, the vine parasite phylloxera, on migrations and metamorphosis in eels, and on termites. He was the first to describe and establish the life cycle of the human malarial parasite, Plasmodium falciparum, and discovered that only female anopheline mosquitoes are capable of transmitting the disease. His works in malaria remain a lasting controversy in the history of Nobel Prizes, because a British army surgeon Ronald Ross, who discovered the transmission of malarial parasite in birds was given the 1902 Nobel Prize in Physiology or Medicine. But Grassi, who demonstrated the complete route of transmission of human Plasmodium, and correctly identified the types of malarial parasite as well as the mosquito vector, Anopheles claviger, was denied. Grassi was the first to demonstrate the life cycle of human dwarf tapeworm Taenia nana, and that this tapeworm does not require an intermediate host, contrary to popular belief. He was the first to demonstrate the direct life cycle of the roundworm Ascaris lumbricoides by self-experimentation. He described canine filarial worm Dipetalonema reconditum, and demonstrated the parasite life cycle in fleas, Pulex irritans. He invented the genus of threadworms Strongyloides. He named the spider Koenenia mirabilis in 1885 after his wife, Maria Koenen. He pioneered the foundation of pest control for phylloxera of grapes. Biography Grassi was born in Rovellasca, Italy, in what is now the Province of Como. His father Luigi Grassi was a municipal official, and mother Costanza Mazzuchelli was a noted peasant of unusual intelligence. His early education was at Saronno. From 1872 he studied medicine at the University of Pavia under professors Camillo Golgi and Giulio Bizzozero and graduated in 1878. After graduation he worked first at Messina in the Naples Zoological Station and the Oceanographic Station founded by Nicolaus Kleinenberg and Anton Dohrn where he studied Chaetognatha, then completed his training at the University of Heidelberg in Germany under the guidance of Karl Gegenbaur and Otto Bütschli. While in Heidelberg, he married Maria Koenen. In 1883 he became Professor of Comparative Zoology at the