(b. Sina, Italy, 28 January 1859; d. Florence, Italy, 17 March 1944),
Chiarugi, one of the most eminent embryologists of the last hundred years, not only helped shape present-day anatomy; he also influenced thousands of medical students as a great teacher.
The son of Pietro Chiarugi, a small trader, and of Elisa Del Puglia, Chiarugi studied medicine at the University of Siena and graduated in 1882 from the University of Turin. In 1884 he was appointed an assistant at the Institute of Anatomy in Siena, and 1886 he was elected professor of anatomy at the Unversity of Siena. Chiarugi was named director of the Institute of Human Anaomy in Florence and professor of descriptive, microscopical, and topographical anatomy in the Medical School of Florence in 1890; from 1900 he was a famous teacher of anatomy for artists; and in 1908 he began to teach embryology as well. He retired from teaching in 1934 but continued his work almost until his death. In 1902 he had founded the Archivio italiano di anatomia e di embriologia, the publication of which he always supervised.
Chiarugi began his anatomical work with studies of the human encephalon: Osservazioni sulle circonvoluzioni frontali (1885) and Studio critico sulla genesidelle delle circonvoluzioni cerebrali (1886). The conclusions of these first studies confirmed the assumptions found in works by Theodor Bischoff, Paul Broca, and Niclaus Rudinger, that the formation of the cerebral convolutions (the gyri of the cerbral cortex), once acquired by the species, is maintained and passed on by heredity.
In embryology, Chiarugi was the first to demonstrate(1887) that the activity of the heart begins in the very first stages of ontogeny, when the nervous connections are not organized, and even befor the morphological differentiation of the primitive myocardium: in chick embryos of nine-ten somites on the second day of incubation, the pulsation of the heart begings before the appearance of myofibrils. Chiarugi’s observed thus proved the theory of cardiac automatism.
Chiarugi also sought in embrayology the explanation of the significance of cerebral nerves and studied the early development of the vagus, accessory, and hypoglosus nerves. Through this research (1888–1894) he showed the dual origin-neural and branchial-of the vagus nerve, and also that its branchial component orignates from at least two somites.
Chiarugi understood that experimental embryology might help to explain the action of some environmental factors on the early stages of the fertilized egg. From 1895 to 1901 he made a series of observations on the effect of such physical agents as light and temperature on the segmentation of the fertilized egg of Salamandrina. He also studied the pathology of the human embryo. For this embryological work Chiarugi was nominated a member of the International Institute of Embryology at Utrecht. In 1926 he published a book on twins, and 1929 the first voulume of his monumental Trattato di embriologia which was completed in 1944.
Original Works. Bibliographies of Chiarugi’s writings are in Archivio italiano di anatomia e di embriologia, 18 , supp. (1922), vii-xxviii; and 39 (1938), i-xi, Among his works are Istituzioni di anatomia dell’uomo, 3 vols (milan, 1904–1917; 2nd ed., 4 vols., 1921–1926; 5th ed, 1938; 9th ed., 1959; 10th ed., 1968), the first modern Italian treatise on anatomy; Atlante di anatomia dell’uomo ad uso degli artisti (Frolrence, 1908), with 20 life-size plates; I gemeli (turin, 1926); Trattato di embriologia, 4 vols. (Milan, 1929–1944); and “ll peso dell’encefalo e delle sue principali partinegli Italiani,” in Atti della R. Accademia d’Italia, Memorie della Classe di scienze Fisiche. Matematiche e Naturali. 14 (1943), 227–391.
II. Secondary Literature. For reliable discussions of Chiarugi’s life and work, see N. Beccari, “La vita e l’opera di Giulio Chiarugi,” in Archivio italiano di anatomia e di embriologia, 50 (1945), 232–257; pietro Franceschini, “L’automatismo del cuore nelle osservazioni di Giulio Chiulio Charugil,” e di Giulio Fano,” in Physis, 2 (1960), 163–183; and “Giulio Chiarugi,” in Scientia medica italica, 8(1960). 269–283; and G. Levi “Giulio Chiarugi ricercatore e maestro,” in Rendiconti dell’ Accademia nazionale dei Lincei, Classe di Scienze Fisiche, Matematiche e Naturali, 7th ser., 27 (1959), fasc. 5.