prof. MUDr. RNDr. Jaroslav Slípka, DrSc.

• https://neviditelnypes.lidovky.cz/veda/historie-znameniti-lekari-v-ceskych-zemich-92.A190701_224222_p_veda_wag/tisk 
• https://ziva.avcr.cz/files/ziva/pdf/jaroslav-slipka-slavi-85-narozeniny.pdf 
• https://ziva.avcr.cz/files/ziva/pdf/vzpomenuti-na-odkaz-jaroslava-slipky.pdf 
• https://vesmir.cz/cz/casopis/archiv-casopisu/1999/cislo-9/stale-zahadny-kopinatec.html 
• https://cs.wikipedia.org/wiki/Jaroslav_Sl%C3%ADpka_(1926)  

My first interests in exploring nature probably began to show when I was about ten, during holidays at my grandmother’s in Dráchov, where I started catching butterflies together with my friend Sláva, the son of the local head teacher Brčák. Before long I had a respectable collection, and I enjoyed identifying individual species using a book called “Joukl.” We also collected caterpillars and began to rear them in “caterpillar jars”—cucumber jars with the host plant inside. My first literary attempts appeared in 1939: excerpts from books on the topic of “how to collect butterflies.” Gradually I learned several hundred species by their Czech and Latin names. At the Kladno grammar school I was taught at the time by an excellent biologist but a poor teacher, Prof. Josef Žofka, who challenged me to prepare a butterfly exhibition for the Kladno museum—perhaps it is still there today. He also encouraged me to write short pieces for the young naturalists’ section of the journal Vesmír. Once a year we were photographed as student authors—I was first published there in 1942, and I even received a diploma and a book signed by Prof. Matoušek for the best contribution of the year. For my school-leaving exam I submitted a “dissertation” titled “The Butterflies of the Kladno Region,” and so my graduation certificate from 1944, alongside the top grade in natural history, also bears the note “in recognition of outstanding knowledge.”

A week after graduation I began digging coal 520 metres underground at the Prago mine in Kladno-Dubí. I collected insects in the timbering of the mine tunnels, but in the end, as a concrete worker within the “Technische Nothilfe,” I built water reservoirs in Ostrava and Kladno. Right after the revolution I entered the so-called wartime semester at the Faculty of Science of Charles University in Prague. I enrolled in the programme “natural history – geography,” intended for secondary-school teachers. Classical natural history was not limited to biology; it comprised zoology, botany, geology, palaeontology, and mineralogy, along with anthropology and genetics. In geography I was interested mainly in physical geography—continental development, karst formations, and glaciation. I had excellent professors from the classical nineteenth-century school: Julius Komárek (zoologist), Václav Brendl (zoologist), Jan Obenberger (entomologist), Oto Jírovec (parasitologist), Josef Augusta (palaeontologist), Radim Kettner (geologist), and, for example, Karel Hrubý (geneticist), Jiří Malý (anthropologist), and others.

Before long I apprenticed under Komárek, who took a liking to me, and under Obenberger, who wanted me to become a museum curator and even recommended me to head the Karlovy Vary museum. Professionally I shifted from butterflies to Diptera, and on Komárek’s advice I devoted myself to the evolutionarily ancient family Tipulidae. I worked on my dissertation in the very room where, thirty years earlier, Einstein had worked (Prague, Viničná 7). That is how I came to my first evolutionary and microscopic-anatomical themes. I defended my dissertation, “Tracheation and the Nervous System of the Larva of Tipula maxima Poda,” in 1949, though it was published only later, in 1951, in the Bulletin of the Czechoslovak Zoological Society. Alongside the dissertation I also published faunistic articles, and I even described three new species (Tipula subinvenusta, Tricyphona nielseni, and Tipula zonaria, femina nova).

My interest in biology, but also geography, led me to the “Young Generation of Czechoslovak Natural Scientists,” where I met Dr. Emil Hadač. With this polar explorer we founded the “Arctic Section of the Natural Science Club” and planned a journey to Greenland to study glacial relicts on the island’s ice-free areas. But the political coup of February 1948 came, and we had to move the expedition from Greenland (the Nuqsuak Peninsula), which after the war was occupied by the US Army, to Iceland. Among the sixteen participants I was the second-youngest member of the expedition. Our flight to Copenhagen and voyage by ship to Reykjavík, as well as the entire three-month activity, were described in the book To the Land of Volcanoes and Glaciers and in Dr. Staněk’s film of the same title.

After returning from the three-month stay in Iceland I prepared to defend my dissertation for the RNDr. doctorate. Around October 1948 I met Doc. Dr. Oto Slabý in Viničná Street; I knew him as a fellow butterfly enthusiast from Kladno, where during the war he had been the company doctor at Poldovka. Slabý had just habilitated under Prof. Frankenberger and was to take over leadership of the Histology and Embryology Institute at the newly established Faculty of Medicine in Pilsen. Right there on the street he offered me a position as assistant at his institute. What a fateful coincidence! I went to Pilsen at once and liked the institute very much. On Slabý’s advice I even applied to study medicine so that I could at least take the histology exam. But I had not yet completed my studies at the Faculty of Science, and I became a first-year medical student; during this time I finished my Prague studies with rigorous exams in zoology and palaeontology and by defending my dissertation, graduating with the RNDr. degree in June 1949. At the same time I was completing my first year of medicine, working as a part-time assistant, and in the spring of 1950 I even married Hana, whom I knew from the Kladno grammar school—and in 1952 our son was born—Jaroslav again.

At the institute, alongside my studies, I threw myself into intensive work, moving from insect systematics to microscopic anatomy. My first studies concerned the structure of insect compound eyes and the so-called Johnston’s organ in insect antennae. At that time the histology of invertebrates was something entirely new. In 1951 the first shipment of radioactive iodine isotope (¹³¹I) arrived in Czechoslovakia, and I used the opportunity to apply it as a marker in crane-fly larvae that I reared in an aquarium, in which I wanted to study the so-called “gills” around the anal opening. After histological processing I produced the first histo-radio-autographic images, on which in 1952 I demonstrated that the anal papillae are not gills but osmoregulatory organs regulating salt uptake. This work was published only in Czech (with a French résumé) in Biologické listy, but it was soon cited abroad and two Americans verified the correctness of my finding. Today we know of similar organs even in vertebrates. Around that time our daughter Zuzana was born (1956).

For the “minimum” examination I submitted a study of a seven-week cyclopic human embryo, demonstrating the origin of the intermaxilla from the frontal process, which the reviewer Prof. Frankenberger rated highly. I then defended my dissertation as the first at the Faculty of Medicine of Charles University in Pilsen and obtained the degree Candidate of Sciences (CSc.) in 1957.

My experience with the branchial region led me to the study of branchiogenic organs. The first was the evolutionary morphology of the thyroid gland, which I chose as the topic of my habilitation thesis. My work on the evolutionary morphology of the thyroid is a very conscientious and extensive monograph of great significance: it deals with the emergence of endocrine function from the endostyle of amphioxus, functioning exocrinely, through the trabecular and later follicular structure of the endocrine thyroid. It also attempts to demonstrate an analogy with the hypopharyngeal groove in insects. The work was highly valued by the reviewers. A key priority was the experimental removal of the pituitary by decapitation of the embryo to interrupt the pituitary–thyroid axis and thereby demonstrate the arrest of thyroid development at the stage of trabecular epithelium (without follicles). The defence took place in spring 1962, after which I became an associate professor of Charles University in histology and embryology.

After my habilitation I received an offer of an expert position at the Faculty of Medicine of the University of Baghdad. I completed an intensive English course and in October took up the post of head of the microanatomy institute at the Baghdad medical faculty. I taught both of my disciplines, at the University of Baghdad as well as at Mustansiriyah University, and I also travelled to faculties in Mosul and Basra, several times to Kufa and to Sulaymaniyah. Sometimes I taught as many as 30 hours a week; there was no time left for science, yet I pursued anthropology, and in freer moments I worked in the Iraqi Museum on skeletal material, especially from Shanidar. In addition to the development of teeth in Sumerian children I also described the “first Siamese twins in the history of humankind,” originating from the Sumerian Tell Hasuna.

I also devoted myself intensively to the history of Mesopotamia and the historical significance of the work of the Czech physician Dr. Vlasta Kálalová and Dr. Emil Roubíček. After four years (1962–1966) I earned a good name in the Arab world and was invited to Baghdad every year for the next twenty years for visiting lectures in embryology. I was also invited for these lecture stays to Egypt, Syria, Libya, and Kuwait. My time in the Arab world, and especially in Iraq, was very important to me—through the Orient I came to know the West, which until then had been inaccessible to me.

From Iraq I could, for example, follow in the literature attempts at extracorporeal cultivation of human embryos being carried out at that time in Italy, and on the way home in 1966 we stopped (though without much success) in Bologna, where the experiments had begun. After returning, I myself began, quite successfully, experiments on cultivating rat embryos in a “glass cradle,” i.e., a tube (containing the uterine horn) sewn onto the flank of a female partially confined in a tunnel of wire mesh. I also worked on experiments with chicken embryos in opened eggs and followed the development of microphthalmia in embryos with distal cranial nerves electrically eliminated. I also observed heart development in embryos implanted with a prospective morphogenetic field from a second embryo. I also studied the absorptive capacity of the uterine mucosa after implantation of particles of nervous tissue. I greatly enjoyed experimental work, but it was my great mistake that I mostly did not publish these results.

In the 1970s, however, there was an enormous expansion of immunology. I became interested again in the tonsil—both as a possible equivalent of the bursa of Fabricius and as a link between lymphoreticular structures (lymph nodes) and lymphoepithelial ones such as the thymus. I studied their relation to exocrine glands and found that sphenoids are formed in pairs and, unlike palatine tonsils, are tied to glands (lymphoglandular organs) and secrete immunoglobulins. At that time my dissertation Evolutionary Morphology of Inconstant Structures of the Epipharynx was created; I defended it and obtained the degree Doctor of Medical Sciences (DrSc., 1979).

In cooperation with Prof. Zavázal I studied secretory Ig in the youngest human embryos and found IgD and IgM in embryos in which lymphocytes are not yet developed! In palatine tonsils I found keratin pearls similar to Hassall’s corpuscles. I described them also in other derivatives of the clefts together with Marta Perry. This brought me to questions of relationships between ectoderm and endoderm and to the concept of gastrodermal epithelium and its application to clinical questions (cholesteatoma). The most serious work of this period are my studies of tonsil development in germ-free animals—germ-free piglets—which I processed in the Czechoslovak Academy of Sciences laboratory in Hrádek. I proved that the development of the lymphoepithelial structure depends on antigenic stimulation. I lectured on this three times in Japan, each time successfully. My Japanese postgraduate student Sumida studied with me in Pilsen and in three months compiled the groundwork for a Ph.D. dissertation on epipharynx development in anencephalics. I also lectured on immunological topics in Canada (Toronto, Hamilton) and in the USA (Chicago).

Tonsillar issues increasingly shifted toward interest in the thymus. I studied extensive comparative material and confirmed on it the archaic development of the thymus compared with the tonsil, which I regard as an evolutionary novelty and a kind of reserve of the immune system for the evolutionary future.

I was interested in the potential of individual clefts to form thymus and described its development in other clefts, emphasizing the developmental relationship to neuroplacodes and thus the participation of ectoderm in the construction of a branchiogenic organ. A valuable work concerned the “spiraculum,” the study of which led me, alongside osmoregulatory pseudobranchs, to the study of mechanoreceptors that play an important role in the dual development of cranial nerves.

Histological sections of shark embryos (Scyliorhinus) (from the collections of the University of Oxford; photo original by J. Slípka) show, from various views, the so-called head cavities—paired epithelial structures of mesodermal origin situated in the anterior part of the developing head. In the upper left is the so-called “golden section,” as Prof. Slípka himself referred to this shark embryo sitting on an enormous yolk sphere and showing, in the median section, the continuity of trunk and head mesoderm (caption by Dr. R. Černý).

Branchiomerism is only a regional part of body metamerism—while studying the sphenoids I noticed the course of the notochord in the cranial base, and I was struck by chordal nodes, which I homologized with the nucleus pulposus in the intervertebral discs of the spine. Several works arose on this theme, and even my Bulgarian postgraduate student Konstantinov produced, with us, a study on the course of the notochord. Thus I arrived at the problem of head development, which already had a tradition at our institute in the work of Slabý. I lectured on this at a large international congress in Pilsen and soon after, in 1989, in Brighton—where my collaboration with Tim Horder from Oxford and Robert Presley from Cardiff began. I then travelled to Oxford for almost twenty years, studying in its rich collections of comparative embryological material the development of the head, mainly in sharks and primitive fishes. It was fascinating work in a scientifically sacred environment, in the Darwinian atmosphere of T. H. Huxley, De Beer, and other giants. I also had access to the newest scientific literature, unavailable at home at the time. I met a number of outstanding scientists in Cambridge as well, and in London I could collaborate in Marta Perry’s laboratory and even became an honorary scientific member of the Anatomy Department at Guy’s Hospital. Our work on the development of amphioxus also arose there; Tim and I lectured on it in Chicago at celebrations of Prof. Gans’s 70th birthday. We then published the head theme, confirming the segmental development of the head, in the monograph Head Problem.

As for my literary activity, I think I followed throughout my life the classical saying “nulla dies sine linea,” (“Not a day without writing“) and that I probably wrote at least a line every day, filling thousands of pages of notes and protocols on the structures observed under the microscope, or philosophically tinged reflections generalizing what I had seen. The more than two hundred published professional communications in the list of my bibliography are only part of the unpublished work that remained as manuscripts in the drawers of my desk. Today I see that the greatest shortcoming of my scientific activities was that, with humble reserve, I hesitated to publish in prestigious foreign journals. That, of course, was also caused by scientific isolation in a world divided at the time.

Yet amid all that science, perhaps I was not a bad teacher. I enjoyed teaching not only my two disciplines (histology and embryology) to general-track students, but also dentistry students, in both Czech and English. In English I lectured not only at home and in a number of Arab countries, but also in Britain, Japan, the USA, and Canada; at various congresses often in German, and even in Russia and Bulgaria in Russian. I also taught at the Faculty of Education and the Faculty of Arts (anthropology) and at the Faculty of Health Studies (embryology, history of medicine) of the University of West Bohemia in Pilsen.

My teaching work led me to write textbooks. I wrote: Outlines of Histology (three editions), Outlines of Embryology, as well as Foundations of Embryology and Foundations of Physical Anthropology.

My literary activity, however, was not limited to my professional fields; it also included humanistic interests. I took part as a co-author in the books: System and Names of Animals (Czechoslovak Academy of Sciences, Prague, 1954), The Enchanted Valley (Osveta, Martin, 1955), To the Land of Volcanoes and Glaciers (Orbis, Prague, 1957), Key to the Fauna of the ČSSR, IV (Czechoslovak Academy of Sciences, Prague, 1978), The Doctor from the House of Trumpeters (Mladá fronta, Prague, 1978), Cookbook of Czech Doctors (Axonite, Prague, 2011).

The duties of a university teacher, besides teaching and research, also include organizational and managerial work. At the Faculty of Medicine I served as a member of the Scientific Council and chair of the Editorial Commission, which I also represented in the university-wide editorial commission of Charles University. For many years I was the guarantor of senior education in the University of the Third Age and a member of the committee of Czech U3As in Prague. I served on various habilitation and doctoral committees, pedagogical and research councils, and disciplinary boards. I was a member of scientific councils at the Faculty of Arts and at the Faculty of Health Studies of the University of West Bohemia.

Professionally, I served as a member of the committee of the Czechoslovak Anatomical Society and after the political change as its chair. I also became an honorary member of the Czech and Slovak, Russian, Bulgarian, and German anatomical societies, and an honorary member of the Czechoslovak Medical Society of J. E. Purkyně. I was also a member of the Zoological Society, the Entomological Society, and the Society for the History of Science and Technology.

In social organizations during the totalitarian period I was involved, as a non-party member, in the so-called Socialist Academy, where as chair of the natural sciences section I was also a member of its central committee in Prague.

After the 1989 change I became intensely involved as a co-founding member of the international humanitarian organization Lions Club International in Pilsen. In 1995 I was elected governor of the entire district of the Czech Republic. From this position I visited Lions world conventions in Birmingham, Chicago, and Bangkok, as well as various meetings at events in Germany, Russia, Austria, and Hungary.

For my work I was honored many times. I consider the most valuable the award of the Gold Medal of Charles University in Prague and the Silver Medals of Palacký University in Olomouc and Masaryk University in Brno, along with the Purkyně, Bolzano, Kolda and other medals. I also greatly value the granting of honorary citizenship of the town of Loket.

Thus, in full work—which was also my hobby—I lived through most of the twentieth century. I survived a terrible war and I also survived treacherous dictators. It was a harsh time, but we certainly were not bored. I tried to isolate myself from distorted ideological influences and, as a non-party man, to live my own human life in my cocoon and to rejoice at every small sign that even social evolution cannot be stopped by foolish political power. I believed in the coming of democracy, though I admit I was losing hope that I would live to see it. Meanwhile world science and technology were developing at a furious pace: I witnessed the beginnings of radio and later television, the beginnings of aviation up to astronautics; from horse-drawn cabs to supercars; from Edison’s telephone to the mobile phone; from a hand-cranked gramophone with a horn to CDs; and from wooden-bead computers and penholders with inserted metal nibs to notebooks on which I am writing this history.

I also experienced the impressive development of biomedicine: I witnessed the birth of antibiotics, the gradual development of biochemistry, endocrinology, and immunology up to molecular biology and the deciphering of the human genome, transplant methodologies, organ replacements, and artificial fertilization. All of this contributed to prolonging human life. But has this civilizational progress contributed to improving the spiritual quality of life? Has advanced civilization made life wiser and more moral? For today we live in an age of an information boom: it is enough to open the internet and, with a single click, obtain an answer to any question from any field of science, technology, or art. The internet on my desk reminds me of a fertilized egg— a zygote—whose nucleus is packed with information in a cluster of DNA; but that is not yet Homo sapiens! And is a person, packed with information from a computer, Homo sapiens? That is at most Homo informatus—a human being perfectly informed, but not educated, and certainly not moral. Information is certainly a necessary raw material, but it must be carefully and thoroughly processed and digested before it becomes part of our mental equipment. Yet that is very laborious work, which the sufficiently informed person usually excuses by a lack of time. And so the information that has only licked his cerebral cortex evaporates again; a person returns to the starting point, and writes emails and text messages where there is no need to care about style or spelling. But perhaps even this information wave is a necessary and lawful part of the humane phase of human evolution. Hardly, however, will it contribute to an increase in morality. That has not changed much since the time of our ancestors from the cave in Iraqi Shanidar.