Giovanni Battista Grassi


Giovanni Battista Grassi : biography

27 March1854 – 4 May 1925

Professional achievements

Anatomy and Entomology

Grassi’s earlier works were on anatomy and then entomology. He studied the development of the vertebral column in bony fishes and also endemic goiter. His studies on bees, myriapods and termites were monumental. He also studied the chetognates and the reproduction of eels, and he described a new species of spider, Koenenia mirabilis in 1885, dedicated to his wife.

He also made significant contribution to the study of the phylloxera of grapes, which he pursued for several years. The notes of his observations La questione fillosserica in Italia (1904) influenced the Italian Ministry of Agriculture, which eventually requested him to do an exhaustive study of this subject. In 1912 he produced a monumental investigation of the morphology and biology of the Italian and other European genera of phylloxera. It was a foundation for systematic control of agricultural pests.


In 1876 Grassi investigated his native hometown Rovellasca for the high mortality of cats and discovered that they were heavily infected with the nematode Dochmius balsami. In 1878, while still a student at the University of Pavia, he discovered anchylostomiasis in Italy from by identifying the eggs from the faeces of infected individuals. He continued to made great impacts on the study of Anguillula intestinalis, filarial worms, Trichocephalus dispar, and Bilharzia. He was the first to show that the human dwarf tapeworm Taenia nana is able to go through its entire life cycle in one animal, without the need of an intermediate host, a notion that had long been rejected. He was also the first to show that the flea Pulex serraticeps is the intermediate host of feline tapeworm Taenia elliptica. Thus he proposed that swallowing of infected fleas (for example, with milk) might be the reason for taeniasis in children. In 1879 he published a work on the life cycle of Strongyloides stercoralis, and erected the genus Strongyloides. In 1890 he, with Salvatore Calandruccio, described Dipetalonema reconditum, a non-pathogenic filarial worm of dogs, and showed that the parasite completed its development in human fleas, Pulex irritans.

The first crucial step in understanding the life cycle of the roundworm Ascaris lumbricoides was demonstrated by Grassi in a grotesque fashion. To solve a century-old puzzle of how infection of roundworm is transmitted from one host to another, he ingested the roundworm eggs and identified the similar eggs from his own faeces after several days. Thus proving that the roundworm is transmitted through direct ingestion from contaminated source.

Malaria and the life cycle of Plasmodium

Grassi made his first contribution on malaria in 1890, when he (with Raimondo Feletti) discovered Haemamoeba vivax, later renamed Plasmodium vivax. He described Proteosoma praecox, the malaria parasite of birds. In 1891 he performed the first inoculation of malaria parasites from one bird into another. He was the first to compile a comprehensive monograph on the identity and impact of different malarial parasites. His work Studi di uno Zoologo Sulla Malaria in 1891 is as relevant today as it was in his time. His description of the specific characteristics responsible for benign tertian (Haemamoeba vivax), malignant tertian (Laverania malariae, renamed P. falciparum) and quartan (Haemamoeba malariae, renamed P. malariae) malaria resolved the confusion of the time. In addition, his monograph also presented the first conclusive depiction that the bite of only female Anopheles mosquitoes could transmit malaria. In a classic experiment, he dispatched 112 volunteers to the Capaccio plains, a malaria-endemic area, protected them from mosquito bites between dusk and dawn, and they did not get malaria (except five of them) compared with 415 unprotected volunteers who all contracted malaria. In 1898 he and Bignami were able to produce the final proof of mosquito transmission of malaria when they fed local mosquitoes (A. claviger) on infected patients and found that uninfected individuals developed malaria through the mosquito bite.