Caspar Friedrich Wolff
- Kobelt's tubules
- Wolffian body (Caspar Friedrich Wolff)
- Wolffian cyst (Caspar Friedrich Wolff)
- Wolffian duct (Caspar Friedrich Wolff)
Biography of Caspar Friedrich Wolff
Kaspar Friedrich Wolff was one of the founders of embryology and established the doctrine of germ layers. He was born in Berlin, the son Johann Wolff, a tailor and his wife Anna Sofia Stiebeler. He began his medical studies at the Medical-Surgical College – Collegium medico-chirurgicum – in Berlin (1753-1754) and in 1755 enrolled at the University of Halle, where he graduated M.D. in 1759 and obtained his doctorate on November 28 that year with the famous dissertation Theoria generationis, In this work he presented his new theory of epigenesis that gave the death-blow to the entire theory of preformation. The dissertation, criticized by Albrecht von Haller (1708-1777) and Charles Bonnet (1720-1793), who found the theory false, ranks among the most important essays ever written in the whole range of biological literature.
In 1761, at the height of the Seven Years War (1756-1763), when Prussia was at war with Russia and several other countries, Wolff became a field doctor in the Prussian army. Through the Geheimrath Christian Andreas von Cothenius (1708-1789) he obtained a post at a field hospital in Breslau (now Wroclaw, Poland) and was able to begin his anatomical research as well as lecturing. As he was gradually relieved of his practical duties, with more opportunity to concentrate on lecturing, having Christian Ludwig Mursinna (1744-1823) as his Amanuensis.
When the seven years war ended in 1763 the field hospitals were closed and both Wolff and Mursinna lost their jobs. Wolff returned to Berlin, now concentrating his efforts on natural history. He was a controversial figure at the faculty, where his attempt in 1764, like a previous attempt in 1762, to obtain permission to lecture were opposed by the professors of the Medical-Surgical College, who had guild privileges to teach medicine. Religious opposition to his theories on generation probably also played a part in this, and perhaps jealousy.
However, he obtained the right to give private lectures, and from 1763 Wolff gave private lectures in anatomy, physiology, and medicine. The following year he restated his theory of generation and replied to Haller’s and Bonnet’s criticism in Theorie von der Generation – further decreasing his chances of obtaining a professorship.
But despite ardent efforts he was unable to obtain a chair. In 1760-1761 the Swiss mathematician Leonhard Euler (1707-1783), on behalf of the Prussian Academy of Science, had tried to obtain a post for Wolff at the St. Petersburger Academy of Sciences. This was unsuccessful, but in 1767, on Euler's initiative, Wolff was ofefred, and accepted, an invitation to St. Petersburg to enter a chair of anatomy and physiology at the St. Petersburg Academy of Sciences.
He travelled to Russia with his wife in May 1767 and later that year presented to the Academy De formatione intestinorum praecipue. During the next twenty-seven years he published thirty one memoirs in the Academy’s Proceedings, including several that were devoted to anatomical research on the muscles of the heart and on connective tissue. He paid special attention to the study of human monstrosities, which were collected in the Academy’s anatomical cabinet (which Wolff directed ) of the Kunstkammer. Surviving manuscripts indicate that Wolff prepared a major work on the “theory of monsters,” in which he attempted to systematize his epigenetic ideas. His sudden death from a brain haemorrhage prevented his completing this project.
In St. Petersburg his most important research was in embryology. As early as in his doctoral thesis of 1759 he had recognised that every individual, both animals and plants go through a development from an egg to a grown individual. Wolff revived Harvey's doctrine of epigenesis – gradual building up of structures – challenging the prevailing theory that each organism develops from a homunculus – or tiny version of an adult – -inside a seed or sperm, the embryo being already preformed and encased in the ovary. Wolff proposed that groups of cells, initially unspecialized, differentiated into various tissues, organs, and systems. This view was later supported by the French pathologist Xavier Bichat (1771-1802).
In the cabbage and chestnut he observed the gradual formation of the leaf layers and the appearance of veins and petioles. This theory comes close to the germ layer theory of Karl Ernst von Baer (1792-1876). In establishing the blossom is a modified leaf, Wolff anticipated the theory of metamorphosis, formulated in 1790 by Johann Wolfgang von Goethe (1749-1832), according to which all the organs of a plant are the result of transformation of leaves.
Wolff's first works found little recognition among his contemporaries. His important work on the intestinal tract in chicks remained almost completely ignored. He reported that the organs arise from undifferentiated material. The basic potential nature and organisation of the structures of the organism are determined by the genetic constitution of the fertilised egg. The work was only rediscovered through Meckel’s translation, and was regarded by the embryologist von Baer as "the greatest masterpiece of scientific observation".