RATHKE, MARTIN HEINRICH

(b. Danzig, Prussia [now Gdansk, Poland], 25 August 1793; d. Konigs-berg, Prussia [now Kaliningrad, U.S.S. R. j, 15 September 1860)

embryology, anatomy.

Rathke was born into a wealthy burgher family. His father was a master shipbuilder. In 1814, after studying at the local Gymnasium in Danzig, he went to the University of Göttingen to study natural history and medicine. In 1817 he left Göttingen for Berlin, where he received the M.D. degree in 1818. He then returned to Danzig, where he practiced medicine and for three years served as assistant master in the city Gymnasium.

In 1825 Rathke became chief physician at the municipal hospital in Danzig, and in 1826 he was named district physician. During this time, he engaged in research and writing. He discovered branchial clefts, plates, and vascular arches in the embryos of the higher abranchiate animals and also published his study of the respiratory organs in birds and animals. In 1829 he was named professor of physiology and pathology at the University of Dorpat. While at Dorpat he traveled extensively in the Baltic states and Finland and visited St. Petersburg and Moscow.

During his travels, Rathke collected considerable information on animal and marine life, but his interests focused increasingly on embryology and comparative anatomy. He had established contact with Baer, who was then a professor at Konigsberg; and he had been a student at Göttingen with Pander. These three men are recognized as the founders of modern embryology. In 1834, when Baer left Königsberg for St. Petersburg, Rathke succeeded him as professor of zoology and anatomy. He joined the faculty at Konigsberg in 1835 and remained there until his death. He was an extremely influential force on the development of the university. Rathke was greatly admired by his students and colleagues and, shortly before his death, was given a twenty-fifth anniversary celebration for his years at Konigsberg. Rathke continued his travels while at Kfinigsberg; in 1839, for example, he visited Norway and Sweden.

Probably Rathke is best known for his discovery of gill slits and gill arches in embryo birds and animals. He followed the cmbryological history of these structures and found that the gill slits eventually disappear and that the blood vessels adapt themselves to the lungs, which develop from an expansion of the front part of the digestive canal. He also described and compared the development of the air sacs of birds and the larynx of birds and mammals. Rathke’s pocket—a small pit on the dorsal side of the oral cavity that marks the point of invagination of the hypophysis in the development of vertebrates—is named after him.

Rathke was also interested in metamorphosis and tried to account for the regressive development of certain organs, including the gills, the tails of the tadpole, and the so-called primordial Wolffian bodies discovered by him. He characterized these bodies as ikhead kidneys“(pronephros) and described how, during early stages of embryonic development, they perform the function of excretal organs; they disappear as true kidneys develop. (In certain animals the efferent ducts of the Wolffian bodies serve as part of the sex organs.)

Rathke thought that regressive organs were either dissolved and reabsorbed by the body or knocked off and eliminated. In the former case they possess blood vessels through which their substance can be absorbed and used by the body; in the latter case they are horny and lack blood vessels. He thought also that the disappearance of one organ is always succeeded by the development of another to take its place—only an altered mode of living during more advanced stages of development can effect the total loss of previously existing organs.

Rathke was interested in marine research and was the first to describe the lancet fish, which previously had been considered the larva of a mollusk. He also wrote several monographs on crustaceans (both independent and parasitic), mollusks, and worms, as well as on a number of vertebrates, including the lemming and various reptiles. He was also interested in the embryonic development of sex organs. Rathke carried some of the embryological investigations launched by his friend Pander to their logical conclusions, but his work in embryology is less well known than that of Baer—perhaps because his generalizations were more embryological than transcendental. Nonetheless his work was as solidly grounded as that of the more influential Baer.

BIBLIOGRAPHY

I. Original Works. Rathke wrote more than 125 articles, monographs, and books. A helpful hibliog. is L. Stieda, in Allgemeine dcutsche biographic, XXVII, 352–355. His major works include De Salamandrarum corporihus adiposis, ovariis et oviductibus, coram cvolutione (Berlin, 1818), his M.D. diss.; Beitrdge zur Geschichte dcr Thierwelt (1820–1824); Bcmcrkungen iiber den hmercn Ban dcr Prick (Danzig, 1826); Untersuehungen iiher die Bildung und Entwickclung das Flusskrcbcs (Leipzig, 1829); and Abhandhmgen zur Bildungs- und Entwicklungsye sehichie der Mensehen und dcr Thiere, 2 vols. (Leipzig,1832–1833).

Later works are Entwickelungsgeschichte der Natter (Konigsberg, 1839); Bcmerkungen iiber den Ban dcs Amphioxus lanccolatttsy eines Fishes aits der Ordmmg dcr Cyctostomas(K onigsberg, 1841); Beit rage zur ver gleichenden Anatomic und Physiologic, Reischemerkungcn aus Skandinavien, ncbst cincm Anhangc iiber die riick-schreitende Metamorphose dcr Thiere(Danzig, 1842);Vber die Entwickelutigen der Krokodile (Brunswick, 1866); and Entwickelungsgeschichte der Wirbeltier (Leipzig, 1861).

II. Secondary Literature. For a discussion of Rathkc’s influence, see Jane M. Oppenheimer, The Non-Specificity of the German Layers,“in Essays in the History of Embryol Ogy and Biology (Cambridge, Mass., 1967), a repr. with updated bibliog. of an article that originally appeared in Quarterly Review of Biology, 15 (1940), 1–27. A brief sketch can also be found in Eric Nordenskiold, History of Biology (New York, 1928).

Vern L. Bullough