Beccari, Nello

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Beccari, Nello

(b. Bagno a Ripoli, near Florence, Italy, 11 January 1883; d. Florence, 20 March 1957)

anatomy.

Beccari, son of Odoardo Beccari, a learned naturalist who explored the interior regions of Borneo, and of Nella Goretti-Flamini, studied in Florence. After receiving his M.D. in 1907, he dedicated himself to anatomical research at the Institute of Human Anatomy of Florence, at that time directed by Giulio Chiarugi. In 1911 he obtained a teaching diploma in human anatomy and was a substitute teacher of anatomy until 1915. He served as a major in the Italian army during World War I and was wounded at the front. In 1919 he returned to civilian life, and two years later was appointed director of the Institute of Human Anatomy at Catania University. In 1925 he agreed to transfer to the University of Florence as director of the Institute of Comparative Anatomy, a position he held until his seventieth year, the legal age limit for teaching.

Beccari was a very learned anatomist. Following the belief of his teacher Chiarugi that “comparative anatomy is the key to the comprehension of human anatomy,” he developed his research essentially on the plan of comparative anatomy: his last book, Anatomia comparata dei vertebrati (only the first two volumes of the five projected were published, in 1951 and 1955), would have been his own definitive statement of his comparative approach. Nevertheless, he also did some work in more traditional descriptive anatomy; for instance, his precise observations on the rhinencephalon in man: on the olfactory gyri (1911), on the anterior perforated substance (1911), and on the hippocampal gyrus (1911).

Beccari was a fine cytologist, as is shown by his little-known observations on the cutaneous glands of sheep (1909), and particularly those on the suborbital glands of Gazella dorcas (1910): he revealed new, interesting details on sebaceous secretion and demonstrated a functional synergism between epithelial cells and melanophores. But Beccari best displayed his ability as a cytologist in his great work on the genesis of the germ cells and on the early cytological differentiation of sex cells. From 1920 to 1925 he worked systematically on the Bufo viridis, aiming at the discovery of the origin of the germ cells and the morphological description of the initial differentiation of sex cells. Beccari confirmed that in vertebrates the germ cells spring from entodermal elements that appear very early in the embryo’s development, but he could not affirm absolutely that in the fertilized egg of vertebrates a genital blastomere exists, already differentiated, in the earlier stages of segmentation. However, the primary germ cells of Bufo are, in the beginning, all alike, not differentiated cytologically at all. But these primary germ cells already have a sex and, contrary to the view of Ernst Haeckel, who called them hermaphroditic, are female. From the systematic study of Bidder’s organ, Beccari could demonstrate that a constant ovogenesis appears before a doubtful abortive spermiogenesis. In Bufo the earlier morphological appearance of cellular sexuality manifests itself as an initial evolution of primary germ cells in a female direction. In addition, the fact that in Bufo all the males come from hermaphrodite larvae confirmed that, in Bufo, the female is the fundamental sex. Sexual determination: the persistence of the primary sex cells to the periphery of the genital crest and the formation, within this, of a cavity—the socalled ovarian pocket—are signs of female development; the migration within the genital crest of primary sex cells and their proliferation, with precocious appearance of interstitial cells, are signs of masculinity.

Beccari’s principal work was done, however, in the field of neurology. Undoubtedly one of the most eminent neurologists of his generation, he based his conclusions on a thorough knowledge of comparative neurology. Beccari collected and arranged his own wide neurological work in his Nevrologia comparata anatomo-funzionale dei vertebrati e dell’uomo (1943). In his book Il problema del neurone (1945) he gives us the measure of his wide critical knowledge. He defended the fundamental principle of the neuron, underlining the fact that the recent discoveries had not invalidated its individuality, even if they modified its character. Beccari also stated (1948) that in vertebrates metamery begins only when the nerves appear; that the arrangement in the spinal cord of neurons for segmental knots is consequent upon the formation of nerves, and not at all the reason for their metameric arrangement.

But Beccari’s most important contributions related to the rhombencephalon. From his first note of 1906 on the Mauthner’s fibers in the Salamandrina perspicillata to his further works (1911, 1913, 1915, 1919), Beccari persistently analyzed and clarified their functional significance in the structure of the rhombencephalon. In 1921 and 1922 he demonstrated the importance of the tegmental centers of the medulla oblongata and of the pons. Beccari’s research also revealed the role of the rhombencephalon in the determination of static extrapyramidal motility.

Beccari was a very able technician, a precise draftsman, and an excellent teacher. He was secretary of the Italian Society of Anatomy from 1929, associate founder of the Italian Society of Experimental Biology, and a member of the National Academy of the Lincei. Because his democratic beliefs were well known, in October 1944, following Florence’s liberation from German occupation, he was chosen to preside over the Faculty of Natural and Physical Sciences of the University of Florence—a position he held until his death.

BIBLIOGRAPHY

Beccari’s books include Elementi di tecnica microscopica (Milan, 1915, 1927,1940); La inversione sperimentale del sesso nei vertebrati (Pavia, 1930); Nevrologia comparata anatamo-funzionale dei vertebrati e dell’uomo (Florence, 1943); Genetica (Florence, 1945); Il problema del neurone, 2 vols. (Florence, 1945–1947); I problemi biologici del sesso (Rome, 1950); and Anatomia comparata dei vertebrati, 2 vols. (Florence, 1951–1955).

There is no complete list of Beccari’s many articles. For his scientific production between 1906 and 1922, see the bibliographical index of anatomical publications of the Institute of Human Anatomy at Florence for the years 1891–1921, in Archivio italiano di anatomia e di embriologia, 18 (1922), Supp.

Among Beccari’s more important articles are “Sullo sviluppo delle ghiandole sudoripare e sebacee nella pecora,” in Archivio italiano di anatomia e di embriologia, 8 (1909), 271–195: “Ricerche intorno alle tasche ed ai corpi ghiandolari suborbitali in varie specie di ruminanti: anatomia, struttura e sviluppo,” ibid., 9 (1910), 660–690; “La sostanza perforata anteriore e suoi rapporti col rinencefalo nel cervello dell’uomo,” ibid., 10 (1911), 261–275: “Le strie olfattorie nel cervello dell’uomo,” in Monitore zoologico italiano, 22 (1911), 255–270; “La superficie degli emisferi cerebrali dell’uomo nelle regioni prossime al rinencefalo,” in Archivio italiano di anatomia e di embriologia, 10 (1911), 482–500; “Studi sulla prima origine delle cellule genitali nei vertebrati. I. Storia delle indagini e stato attuale della questione,” ibid., 18 (1920), 157–190; “II. Ricerche nella Salamandrina perspicillata,” ibid., 18 (1921), Supp.29; “III. e IV. Ovogenesi larvale, organo del Bidder e differenziamento dei sessi nel Bufo viridis,” ibid., 21 (1924) and 22 (1925); and “II problema del differenziamento del sesso negli anfibi,” in Archivio di fisiologia, 23 (1925), 385–410.

See also “Dimostrazione delle fibre di Mauthner nella Salamandrina perspicillata,” in Lo sperimentale, 60 (1906), 456–460; “Ricerche sulle cellule e fibre del Mauthner e sulle loro connessioni in pesci ed anfibi,” in Archivio italiano di anatomia e di embriologia, 6 (1907), 660–700; “Le cellule dorsali o posteriori dei ciclostomi. Ricerche nel Petromyzon marinus,” in Monitore zoologico italiano, 20 (1909), 308–325; “Sopra alcuni rapporti del fascicolo longitudinale posteriore con i nuclei di origine dei nervi oculomotore e trochleare nei teleosei,” ibid., 242–255; “La costituzione, i nuclei terminali e le vie di connessione del nervo acustico nella Lacerta muralis Merr.,” in Archvio italiano di anatomia e di embriologia, 10 (1911), 646–660; “Sulla spettanza delle fibre del Lenhossek al sistema del nervo accessorio. Osservazioni in Lacerta muralis,” ibid., 11 (1912), 299–315; “II IX, X, XI e XII paio di nervi cranici ed i nervi cervicali negli embrioni di Lacerta muralis,” ibid., 13 (1915), 1–25; “Duplicità delle cellule e delle fibre del Mauthner in un avanotto di trota,” in Monitore zoologico italiano, 30 (1919), 88–100; “Peculiari modalità nelle connessioni di alcuni neuroni del sistema nervoso centrale dei pesci. Ulteriori ricerche sulle collaterali delle fibre del Mauthner,” in Archivio italiano di anatomia e di embriologia, 17 (1919), 239–360; “Lo scheletro, i miotomi e le radici nervose nella regione occipitale degli avanotti di trota,” ibid., 19 (1921), 1–45; “Studi comparativi sulla struttura di rombencefalo. I. Nervi spino-occipitali e nervo ipoglosso. II. Centri tegmentali,” ibid., 122–210; “II centro tegmentale o insterstiziale ed altre formazioni poco note nel mesencefalo e nel diencefalo di un rettile,” ibid., 20 (1923), 560–573; “La costituzione del nucleo del fascio ottico basale dei rettili, e la sua probabile importanza nella produzione del riflesso pupillare,” in Atti del VI⁰ Congresso della Società Italiana di Neurologia (Naples, 1923); “Primo differenziamento dei nuclei motori di nervi cranici,” in Monitore zoologico italiano, 34 (1923), 161–170; “I centri tegmentali dell’asse cerebrale dei selaci,” in Archivio zoologico italiano, 14 (1930), 411–455; “Studi comparativi sopra i nuclei terminali del nervo acustico nei pesci,” ibid., 16 (1931), 732–760 “Intorno all’esistenza di uno strato sinaptico nelle connessioni di alcuni neuroni dei pesci,” in Monitore zoologico italiano, 45 (1934), 220–235; and “Morfogenesi filetica e morfogenesi embrionale del sistema nervoso dei vertebrati,” report to the Ninth Congress of the Società Italiana di Anatomia (Bologna, 24–27 October 1947), ibid., Supp. 56 (1948), 22–32.