On October 7, 1822, German zoologist Karl Georg Friedrich Rudolf Leuckart was born. He is known to be one of the initiators of modern parasitology. Leuckart described the complicated life histories of various parasites, including tapeworms and the liver fluke, and demonstrated that some human diseases, such as trichinosis, are caused by multicellular animals of the various wormlike phyla.
“Nowhere is it more true that “prevention is better than cure,” than in the case of Parasitic Diseases.”
— Rudolf Leuckart
Rudolf Leuckart – Early Years
Rudolf Leuckart was born in Helmstedt, Lower Saxony as son of Gottfried Leuckart, print shop owner and councilman, and nephew of famous surgeon and natural scientist Friedrich Andreas Sigismund Leuckart (1794–1843). His mother Friederike Dorothea Charlotte (1785-1834) was the daughter of the coppersmith, copper trader and brewer Leberecht Christian Philipp Theuerkauf (1739-90) from Helmstedt. It was his uncle, who made a strong impression on Leuckart and awakened his love for zoology. As a youth, he showed an early interest in zoology and in insects in particular. In 1842, he enrolled at the university of Göttingen to study medical and natural sciences, where he studied under the renowned zoologist, Rudolph Wagner, with whom he formed a lifelong friendship and who encouraged him to research in this branch of science. In 1845 he finished his doctoral thesis (De monstris eorumque causis et ortu) with distinction and subsequently habilitated in 1847 as “Privatdozent” (outside lecturer) in physiology and zoology with a study on the system on marine invertebrates.
Two New Phyla
For his habilitation thesis, Leuckart had carried out studies mainly on the North Sea. A result of this work was the division of Georges Cuvier’s Radiata into into two phyla: Coelenterata and Echinodermata (terms of his own devising). The result marked the beginning of a new period of scientific zoology, that of animal systematics based on subtle morphological investigations. The publication of this study as a result of his expedition to the North Sea, soon raised his popularity among fellow scientists.
Research in Parasitology
In 1850 at age 28, he became a professor of zoology at the University of Giessen, where Justus von Liebig and the anatomist and embryologist Theodor Bischoff were attracting many young researchers. Leuckart is remembered for his work in parasitology, particularly research regarding tapeworm and trichinosis. He was especially interested in the sexual organs of the lower animals and in parthenogenesis, as well as in polymorphism, a term he originated. He was the first to prove that Taenia saginata occurs only in cattle (and humans), and Taenia solium occurs only in swine (and humans). His study of Trichina helped support Rudolf Virchow‘s campaign to create meat inspection laws in Germany. With Virchow and Friedrich Albert von Zenker, he was the first to document the life cycle of the parasite Trichinella spiralis in swine and humans. He also did important studies of the sheep liver fluke.
Zoological Wall Charts
In 1869 Leuckart accepted an offer from the University of Leipzig. The facilities at his disposal were at first inadequate, but in 1880 he was given a new zoological institute constructed according to his plans and furnished with laboratories, a museum, and a library. Zoologists from all over the world came to the institute as guest researchers. Leuckart’s outstanding skill as a teacher and his clear delivery brought him many students who later held chairs of zoology all over the world. In the field of entomology, he conducted investigations into the micropyle and fertilization of insect eggs, the reproduction and development involving members of Pupipara, parthenogenesis among insects, and studies on the anatomy and life history of the honeybee. Between 1877 and 1892, he developed a series of zoological wall charts that have been used worldwide as teaching aids.
The respect paid to Leuckart for his achievements is attested by many honors. Among other things, the German Zoological Society, of which he was the first president from 1890 to 1891, made him its first honorary member, he became an honorary citizen of Leipzig, and the Leipzig sculptor Carl Seffner was commissioned to make a marble bust of him in honor of Leuckart, which is now owned by the University of Leipzig. In 1853 Leuckart was appointed a member of the Leopoldina. In 1859, he was elected a corresponding member of the Göttingen Academy of Sciences. In December 1864, he became an honorary fellow of the Royal Society of Edinburgh. From 1868, he was a foreign member of the Bavarian Society of Sciences and Humanities and, from 1869, a full member of the Royal Saxon Society of Sciences in Leipzig. In 1877 he was elected to the American Academy of Arts and Sciences and in 1887 he became a corresponding member of the Prussian Academy of Sciences. In 1861, he was accepted as a corresponding member of the Russian Academy of Sciences in St. Petersburg, and from 1895 he was its honorary member. Leuckert was also a member of the National Academy of Sciences from 1895.
The fruit of Leuckart’s research in parasitology, the two-volume Die menschlichen parasiten und die von ihnen herrührenden Krankheiten (Human parasites and diseases caused by them), was never completed; the aging Leuckart did not find the strength to finish it. Nevertheless, it has become a classic of parasitology. Today the “Rudolf-Leuckart-Medaille” is an annual award for research in parasitology by the Deutschen Gesellschaft für Parasitologie (German Society of Parasitology).
“It is not possible for man, as a thinking being, to close his mind to the knowledge that he is ruled by the same power as is the animal world. Like the despised worm he lives in dependence upon external commands, and like the worn he perishes, even when he has shaken the world through the power of his ideas.” (Richard Leuckart)
Introduction to Medical Parasitology lecture, 
References and Further Reading:
-  Karl Georg Friedrich Rudolf Leuckart at encyclopedia
-  Rudolph Virchow – the Father of Modern Pathology, SciHi Blog
-  Louis Pasteur – the Father of Medical Microbiology , SciHi Blog
-  George Cuvier and the Fossils, SciHi Blog
-  Rudolf Leuckart (1848) Ueber die Morphologie und die Verwandtschaftsverhältnisse der wirbellosen Thiere
-  Rudolf Leuckart at Wikidata
-  Introduction to Medical Parasitology lecture, Medical Microbiology Guide @ youtube
-  Lukács, D (February 1978). “Karl Georg Friedrich Rudolf Leuckart, founder of parasitology”. Orvosi Hetilap. 119 (6): 341–3.
-  Hans Querner: Leuckart, Rudolf. In: Neue Deutsche Biographie (NDB). Band 14, Duncker & Humblot, Berlin 1985, S. 372 f
-  Timeline of Rudolf Leuckart via Wikidata
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