RETZIUS, ANDERS ADOLF

(b. Stockholm, Sweden, 13 October 1796; d. Stockholm, 18 April 1860)

anatomy, histology, anthropology.

Retzius holds a distinguished place among nineteenth-century biologists for his contributions to comparative anatomy, histology, and anthropology, and as a pioneer of these disciplines in Scandinavia. He played a prominent role in the development of biological science there between 1820 and 1860, especially in the establishment of the Karolinska Institutet in Stockholm, and was one of those who guided Swedish biology and medicine into scientific channels against the strong influence of the speculative Naturphilosophie prevalent in many of the German universities.

Retzius’ father, Anders Jahan Retzius (1742–1821), was professor of natural history at the University of Lund. One of his major accomplishments was to assemble an important collection of minerals and rocks for the university. Reizius was introduced to natural history, especially zoology, by his father; and when he entered the University of Lund, he came under the influence of Arived Henrik Florman, professor of anatomy, who initiated him into the methods of dissection and careful observation. In 1816 he spent a year at Copenhagen with the anatomist Ludwig Levin Jacobson, the physicist Hans Christian Oersted, and zoologist J. H. Reinhard. The latter, a disciple of Cuvier, impressed young Retzius with his scholarly lectures on comparative anatomy, illustrated with his own preparations. After his return Retzius finished his medical studies with a dissertation on the anatomy of cartilaginous fishes, especially the dogfish and the ray, Observationes in anatomiam chondropterygium praecipue squali et rajae generum (lund, 1819).

In 1823 Retzius was appointed professor of veterinary science at the Stockholm Veterinary Institution, and in 1824, sponsored by Berzelius, he also became professor of anatomy at the Karolinska Medico-Kirurgiska Institutet. In 1830 he was awarded the additional post of inspector of the Karolinska institutet and was, besides Berzelius, the stongest personality in its early development. In 1840 he resigned his post at the Veterinary Institution and until his death devoted all his time to the two posts he held at the Karolinska Institutet.

Retzius’ scientific work began with comparative anatomy, which he pioneered in Sweden and made a subject of medical training. During the studies for his inaugural dissertation he discovered the interrenal organ of elasmobranch fishes which is—as was shown later—homologous with the adrenal cortex of higher animals. A few years later (1822) he studied in detail a still more primitive vertebrate, the slime eel (Myxine glutinosa), a curious animal placed by previous naturalists in such different groups as mollusks, fishes, and even amphibians. Retzius described in two brief but significant studies (1822 and 1824) its complicated cartilaginous cranium, digestive system, pronephric ducts (the pronephros itself was discovered later by J. Müller), and a gland shown later (also by Müller) to be homologous with the adrenal organ of higher forms. His descriptions of the vascular system and of the small but complex brain were almost complete. He also described the cranial, vagus, trigeminal, facialis, and statoacusticus nerves and the simply constructed internal ear, which has only one semi-circular canal. Retzius’ work on Myxime was a basis for further research by Johannes Müller, who described this creature—one of the few surviving links between vertebrates and the lowest chordtes—more completely in a series of treatises (1834–1845) and usually receives credit for all the work on Myxime.

Retzius’ work on the slime eel was related to his research on Amphioxus, the only link between vertebrates and invertebrates. Amphioxus had been described by Pallas as Limax lanceolatus (a mollusk) in 1774; in the 1830’s it was found by O.G. Costa at Naples and by Lovén and Sunderwall on the Swedish coast. Costa recognized the kinship of the animal, which he named Branchiostoma lubrum, to the lowest fish; and W. Yarrell in 1836 identified the dorsal cord, named the creature Amphioxue lanceolatus, and classed it with the Cyclostomata. Retzius notices several new features of this animal. He informed Muller of his findings and, because his vision was deteriorating, invited Muller to accompany him to Bohuslan, where they could investigate the living animals in detail. In just twelve days in September 1841 the investigation of Amphioxus ’ morphology was completed, and Müller presented the results to the Berlin Academy of Sciences on 6 December. Investigations of the Amphioxus, pursued mainly by A. Kovalevski, had great importance in the development of comparative anatomy and embryology.

In his other early anatomical work, Retzius described, with J. S. Billing, the ciliary and sphenopalatine ganglia in the horse and found the connections between the sympathetic trunk and the cerebrospinal merves. Through his injection methods he discovered the peripheral canal of the cornea (later called Schlemm’s canal) and demonstrated several previously unknown anastomoses in the vascular system. A study of skeletons of birds in 1824 aroused his interest in the avian respiratory system and in the particular connections of the air sacs with the cavities of the long bones. He also compared avian and reptilian lungs.

In the period 1824–1835 Retzius made several journeys to other parts of Europe and to England, where he met many scientists and participated in several scientific meetings At a memorable meeting of German naturalists and physicians in Berlin in 1828 Retzius invited K. E. von Baer to use a dog to demonstrate the mammalian ovum, his famous discovery which had been made public at the beginning of that year but had not been mentioned to Baer by any other participant at the meeting. In 1833, after a journey to England, France, Germany, and Austria, Retzius attended one of the yearly congresses at Breslau. While there he worked with Purkyň, who introduced him to the use of the microscope and the techniques of preparing tissues for microscopic observations, in particularly hard tissues, bone, and teeth (grinding, decalcification).

This new knowledge and practical experience marked a turning point in Retzius’ research, for after his return to Stockholm he began a series of microscopic studies—the most important of which were those of the structure of the teeth of several animal species. His work and that of Purkyne on this topic had a great effect and stimulated others, particularly in England (John Tomes, Owen, Huxley), to study the structure and development of teeth; A. Nasmyth quoted extensively from Retzius’ and Purkyň’s works. The term “Retzius’ striae” for brown parallel lines crossing the enamel prisms bears witness to his precise observations and lasting contributions in this field.

During these studies, about 1840, it became evident that Retzius’ eyesight had greatly deteriorated, and he had to abandon microscopic studies. For the last two decades of his life, he turned to gross anatomy, chiefly of the skeletal, circulatory, and nervous systems; to topographical anatomy; and to physical anthropology. The distinction of the pyloric antrum and the pyloric canal and the description, in the fundus of human and rodent stomachs, of the gastric canal, a gutterlike groove allowing a direct passage from cardia to the pylorus, are important original findings. The latter was forgotten, and was not confirmed and accepted until the beginning of the twentieth century. In topographical anatomy Retzius is known for Retzius’ cavity, the prevesical space between the symphysis, the bladder, and the anterior abdominal wall that contains loose connective tissue and fat and affords the surgeon access to the bladder without opening the peritoneal cavity. “Retzius’ ligament” commemorates his description of this structure, also called the fundiform ligament, on the ventral side of the ankle joint.

Retzius’ most important work seems to have been in anthropology, where, following J. F. Blumenbach, he attempted to work out a way of classifying human ethnic groups according to their physical characters. After the discovery of numerous human remains in prehistoric graves in Scandinavia, Retzius noticed during their investigations considerable variation in the shape of the cranium. He extended his research to other European ethnic groups and found that human skulls could be divided, according to the proportion of length to breadth, into long (dolichocephalic) and short (brachycephalic), each race having a constant ratio between the breadth and length (cephalic index). Another division could be made according to the shape of the facial bones: orthognathous and prognathous.

The value of this work is not so much in Retzius’ conclusions—in the division of populations according to their craniometric characters—but in his demonstrating the possibility of quantitative expression of different patterns of bodily forms and their mathematical treatment. Craniometric and anthropometric methods were soon widely adopted and developed, and new indexes were introduced. Thus there emerged a new branch of science—physical anthropology.

BIBLIOGRAPHY

I. Original Works. Most of Retzius’ writings are short articles or communications to scientific meetings written in Swedish and presented as factual reports of his findings, without theoretical reasoning or discussion of earlier work. A list of his published works is in S. Lovö n, “Anders Adolf Retzius,” in Lefnadsteckningar öfver Svenska Vetenskaps akademiens ledamöter, 2 (1878–1885), 20–36. Most of his important works were also published in German in Archiv für Anatomic und Physiologic (1826–1849) or in Notizen aus dem Gebiete der Natur- und Heilkunde. They include “Bemerkungen über den innern Bau der Zähne, mit besonderer Rücksicht auf den in Zahnknochen vorkommenden Röhrenbau, … mit-geteilt in Briefen an den Dr. Creplin in Greifswald …,” in Archiv für Anatomic, Physiologie, und wissenschaftliche Medizin (1837), 486–566—extensive quotations in English are in A. Nasmyth, Researches on the Development, Structure and Diseases of the Teeth, I, Historical Introduction (London, 1839); “Ueber die Schädelformen der Nordbewohner,” fa Archiv für Anatomie, Physiologie und wissenschaftliche Medizin (1845), 84–129; “Bemerkungen über Schädel von Guarani-lndianern aus Brasilien,” ibid. (1849), 543–553; “Kraniologisches,” ibid., 554–582; “Ueber das Ligamentum pelvioprostaticum oder den Apparat, durch welchen die Harnblase, die Prostata und die Harnrühre an der untern Beckenöffnung befestigt sind,” ibid., 182–190; and “Ueber die richtige Deutung der Seitenfortsötze an den Rücken- und Lendenwirbeln beim Menschen und bei den Säugethieren,” ibid., 593–685.

After Retzius’ death a collection of anthropological writings was published in Swedish, Samlade skrifter at etnologiskt innehall (Stockholm, 1864) and in German Ethnologische Schriften von Anders Retzius, nach dem Tode des Verfassers gesammelt (Stockholm, 1864). Later his son Gustaf published another collection, Skrifter i skilda ämnen, jämte några bref af Anders Retzius (Stockholm, 1902), containing a history of the development of anatomy in northern Scandinavia, biographical sketches (mainly of Swedish scientists), and papers of more general interest. This volume includes also Retzius’ letters to the Finnish anatomist E. J. Bonsdorff. See also C. M. Fürst, “Arvid Flormans bref till Anders Retzius,” in Lund Univ. Årsskrift, 6, no. 5 (1910). W. Haberling included many letters by Retzius in his Johannes Müller, das Leben des rheinischen Natur forschers auf Grund neuer Quellen und seiner Briefe (Leipzig, 1924). Other letters were published by V. Kruta in “Anders Retzius und Johannes Ev. Purkyně,” in Lychnos (1956), 96–131, and (1959), 222–227; and B. Ottow, in Ein Briefwechsel zwisehen Anders Adolf Retzius und Karl Ernst von Baer (Stockholm, 1963).

II. Secondary Literature. Several biographies were published in Swedish, including one by Erik Müller, who had access to Retzius’ papers and writings: “Anatomiska institutionen i Stockholm 1756–1910,” in Karolinska Mediko’kirurgiska Institutets historia, 111 (Stockholm, 1910), 94–122. A short but comprehensive biography in English is O. Larsell, “Anders Adolf Retzius (1796–1860),” in Annals of Medical History, 6 (1924), 16–24.

Vladislav Kruta