Ernst Haeckel, in full Ernst Heinrich Philipp August Haeckel
(born Feb. 16, 1834, Potsdam, Prussia [Germany] – died Aug. 9, 1919, Jena, Germany.),
German zoologist and evolutionist who was a strong proponent of Darwinism and who proposed new notions of the evolutionary descent of human beings. He declared that ontogeny (the embryology and development of the individual) briefly, and sometimes necessarily incompletely, recapitulated, or repeated, phylogeny (the developmental history of the species or race).
Haeckel grew up in Merseburg, where his father was a government official. He studied at Würzburg and at the University of Berlin. The turning point in Haeckel’s thinking was his reading of Charles Darwin’s 1859 work, On the Origin of Species by Means of Natural Selection. Meanwhile, he completed a dissertation in zoology in 1861 at Jena and became privatdozent there. In 1862 he was appointed associate professor of zoology, and that year, when he published his monograph on the Radiolaria, he expressed in it his agreement with Darwin’s theory of evolution; from that time he was a proponent of Darwinism, and he soon was lecturing to scientific and lay audiences on the descent theory. Darwin had described evolution through the natural selection of accumulated favourable variations that in time formed new species; to Haeckel, however, this was only a beginning, with consequences to be pursued further. In 1865 he was appointed full professor, and he remained at Jena until his retirement in 1909.
Haeckel saw evolution as the basis for a unified explanation of all nature and the rationale of a philosophical approach that denied final causes and the teleology of the church. His Generelle Morphologie der Organismen (1866; “General Morphology of Organisms”) presented many of his evolutionary ideas, but the scientific community was little interested. He set forth his ideas in popular writings, all of which were widely read though they were deplored by many of Haeckel’s scientific colleagues.
Haeckel brought attention to important biological questions. His gastraea theory, tracing all multicellular animals to a hypothetical two-layered ancestor, stimulated both discussion and investigation. His propensities to systematization along evolutionary lines led to his valuable contributions to the knowledge of such invertebrates as medusae, radiolarians, siphonophores, and calcareous sponges.
Building collections around his own, Haeckel founded both the Phyletic Museum in Jena and the Ernst Haeckel Haus; the latter contains his books and archives, and it preserves many other mementos of his life and work.
Haeckel died at Jena, Germany, on August, 9, 1919.
To the 110th anniversary of George David Wald
George David Wald (November 18, 1906 – April 12, 1997) was an American scientist who was best known for his work with pigments in the retina. He won a share of the 1967 Nobel Prize in Physiology or Medicine with Haldan Keffer Hartline and Ragnar Granit.
As a postdoctoral researcher, Wald discovered that vitamin A was a component of the retina. His further experiments showed that when the pigment rhodopsin was exposed to light, it yielded the protein opsin and a compound containing vitamin A. This suggested that vitamin A was essential in retinal function.
In the 1950s, Wald and his colleagues used chemical methods to extract pigments from the retina. Then, using a spectrophotometer, they were able to measure the light absorbance of the pigments. Since the absorbance of light by retina pigments corresponds to the wavelengths that best activate photoreceptor cells, this experiment showed the wavelengths that the eye could best detect. However, since rod cells make up most of the retina, what Wald and his colleagues were specifically measuring was the absorbance of rhodopsin, the main photopigment in rods. Later, with a technique called microspectrophotometry, he was able to measure the absorbance directly from cells, rather than from an extract of the pigments. This allowed Wald to determine the absorbance of pigments in the cone cells (Goldstein, 2001).
To the 240th anniversary of René Joachim Henri Dutrochet
René Joachim Henri Dutrochet (November 14, 1776 – February 4, 1847) was a French physician, botanist and physiologist. He is best known for his investigation into osmosis.
Dutrochet was born in Néons to a noble family, soon ruined in the French Revolution. In 1799 he entered the military marine at Rochefort, but soon left it to join the Vendean army. He then left it to tend to his family’s manor in Touraine. There, he was a keen addition to the scientific nation.
His scientific publications were numerous, and covered a wide field, but his most noteworthy work was embryological. His Recherches sur l’accroissement et la reproduction des végétaux, published in the Mémoires du museum d’histoire naturelle for 1821, procured him in that year the French Academys prize for experimental physiology. In 1837 appeared his Mémoires pour servir a l’histoire anatomique et physiologique des végétaux et des animaux, a collection of all his more important biological papers.
He investigated and described osmosis, respiration, embryology, and the effect of light on plants. He has been given credit for discovering cell biology and cells in plants and the actual discovery of the process of osmosis. His early researches into the voice introduced the first modern concept of vocal cord movement.
The Mauritian plant genus Trochetia was named in his honour.
To the 245th anniversary of Marie François Xavier Bichat
Marie François Xavier Bichat (14 November 1771 – 22 July 1802) was a French anatomist and pathologist; he is known as the father of histology. Although working without the microscope, Bichat distinguished 21 types of elementary tissues from which the organs of human body are composed.
Bichat was born at Thoirette in Jura, France. His father was Jean-Baptise Bichat, a physician who had trained at Montpellier and was Bichat’s first instructor. His mother was Jeanne-Rose Bichat, his father’s wife and cousin. He entered the college of Nantua, and later studied at Lyon. He made rapid progress in mathematics and the physical sciences, but ultimately devoted himself to the study of anatomy and surgery under the guidance of Marc-Antoine Petit (1766–1811), chief surgeon to the Hotel-Dieu at Lyon.
At age 29 he was appointed as the chief physician to the Hotel-Dieu. In 1796, he and several other colleagues formally founded the Société d’Emulation de Paris, which provided an intellectual platform for debating problems in medicine. He died at age 30, fourteen days after falling down a set of stairs at Hotel-Dieu and acquiring a fever.He is buried at Père Lachaise Cemetery.
Œuvres chirurgicales de Desault, ou tableau de sa doctrine, et de sa pratique dens le traitement des maladies externes (1798–1799), a work in which, although he professes only to set forth the ideas of another, he develops them with the clearness of one who is a master of the subject. In 1797, he began a course of anatomical demonstrations, and his success encouraged him to extend the plan of his lectures, and boldly to announce a course of operative surgery.
Bichat’s main contribution to medicine and physiology was his perception that the diverse body of organs contain particular tissues or membranes, and he described 21 such membranes, including connective, muscle, and nerve tissue. Bichat did not use a microscope because he distrusted it, therefore his analyses did not include any acknowledgement of cellular structure. Nonetheless, he formed an important bridge between the organ pathology of Giovanni Battista Morgagni and the cell pathology of Rudolf Ludwig Carl Virchow.
To the 100th Anniversary of Heinrich Waldeyer
Heinrich Wilhelm Gottfried von Waldeyer-Hartz (6 October 1836 – 23 January 1921) was a German anatomist, famous for consolidating the neuron theory of organization of the nervous system and for naming the chromosome. He is also remembered in two macroanatomical structures of the human body which were named after him: Waldeyer’s tonsillar ring (the lymphoid tissue ring of the naso- and oropharynx) and Waldeyer’s glands (of the eyelids).
Waldeyer’s name is sometimes associated in neuroscience with the so-called “neuron theory” and for popularizing the term “neuron” to describe the basic structural unit of the nervous system. Waldeyer used the path-breaking discoveries by neuroanatomists (and later Nobel Prize winners) Camillo Golgi (1843–1926) and Santiago Ramón y Cajal (1852–1934), who had used the silver nitrate method of staining nerve tissue (Golgi’s method) to formulate a short brilliant synthesis, even though he did not contribute with any original observations.
Waldeyer also studied the basophilic stained filaments which had been found to be the main constituents of chromatin, the material inside the cell nucleus, by his colleague of Kiel, Walther Flemming (1843–1905). Although its significance for genetics and for cell biology was still to be discovered, these filaments were known to be involved in the phenomenon of cell division discovered by Flemming, named mitosis, as well as in meiosis. He coined in 1888 the term “chromosome” (1888) to describe them.
Among his many other anatomical and embryological studies, Waldeyer became known for his pioneering research on the development of teeth and hair, many of the terms he invented are still in use today. He also published the first embryological, anatomical and functional studies about the naso-oro-pharyngeal lymphatic tissue, which received his name.
To the 150th Anniversary of the Nobel Laureate,
Charles Jules Henry Nicolle
Epidemic typhus is a form of typhus so named because the disease often causes epidemics following wars and natural disasters. The causative organism is Rickettsia prowazekii, transmitted by the human body louse (Pediculus humanus humanus). The first description of typhus was probably given in 1083 at La Cava abbey near Salerno, Italy. In 1546, Girolamo Fracastoro, a Florentine physician, described typhus in his famous treatise on viruses and contagion, De Contagione et Contagiosis Morbis.
Before a vaccine was developed during World War II, typhus was a devastating disease for humans and has been responsible for a number of epidemics throughout history. These epidemics tend to follow wars, famine, and other conditions that result in mass casualties.
Charles Jules Henry Nicolle (21 September 1866 Rouen – 28 February 1936 Tunis) was a French bacteriologist who received the Nobel Prize in Medicine for his identification of lice as the transmitter of epidemic typhus. He learned about biology early from his father Eugène Nicolle, a doctor at a Rouen hospital. He was educated at the Lycée Pierre Corneille in Rouen. He received his M.D. in 1893 from the Pasteur Institute. At this point he returned to Rouen, as a member of the Medical Faculty until 1896 and then as Director of the Bacteriological Laboratory.
In 1903 Nicolle became Director of the Pasteur Institute in Tunis, where he did his Nobel Prize-winning work on typhus, bringing Hélène Sparrow with him as laboratory chief. He was still director of the Institute when he died in 1936. He was a key researcher in discovering a deadly organism, toxoplasmosis.
He also wrote fiction and philosophy through his life, including the books Le Pâtissier de Bellone, Les deux Larrons, and Les Contes de Marmouse.
Nicolle’s discovery came about first from his observation that, while epidemic typhus patients were able to infect other patients inside and outside the hospital, and their very clothes seemed to spread the disease, they were no longer infectious when they had had a hot bath and a change of clothes. Once he realized this, he reasoned that it was most likely that lice were the vector for epidemic typhus.
In June 1909 Nicolle tested his theory by infecting a chimpanzee with typhus, retrieving the lice from it, and placing it on a healthy chimpanzee. Within 10 days the second chimpanzee had typhus as well. After repeating his experiment he was sure of it: lice were the carriers.
Further research showed that the major transmission method was not louse bites but excrement: lice infected with typhus turn red and die after a couple of weeks, but in the meantime they excrete a large number of microbes. When a small quantity of this is rubbed on the skin or eye, an infection occurs.
Nicolle surmised that he could make a simple vaccine by crushing up the lice and mixing it with blood serum from recovered patients. He first tried this vaccine on himself, and when he stayed healthy he tried it on a few children (because of their better immune systems), who developed typhus but recovered.
He did not succeed in his effort to develop a practical vaccine. The next step would be taken by Rudolf Weigl in 1930.
Werner Theodor Otto Forßmann (29 August 1904 – 1 June 1979) was a physician from Germany who shared the 1956 Nobel Prize in Medicine (with Andre Cournand and Dickinson Richards) for developing a procedure that allowed for cardiac catheterization. In 1929, he put himself under local anesthesia and inserted a catheter into a vein of his arm. Not knowing if the catheter might pierce a vein, he put his life at risk. Forssmann was nevertheless successful; he safely passed the catheter into his heart.
Forssmann was born in Berlin on 29 August 1904. Upon graduating from Askanisches Gymnasium, he entered the University of Berlin to study medicine, passing the State Examination in 1929.
He hypothesized that a catheter could be inserted directly into the heart, for such applications as directly delivering drugs, injecting radiopaque dyes, or measuring blood pressure. The fear at the time was that such an intrusion into the heart would be fatal. To prove his point, he decided to try the experiment on himself.
In 1929, while working in Eberswalde, he performed the first human cardiac catheterization.
After winning the Nobel Prize, he was given the position of Honorary Professor of Surgery and Urology at the University of Mainz. In 1961, he became an honorary professor at the National University of Córdoba. In 1962, he became a member of the Executive Board of the German Society of Surgery. He also became a member of the American College of Chest Physicians, honorary member of the Swedish Society of Cardiology, the German Society of Urology, and the German Child Welfare Association.
He died in Schopfheim, Germany of heart failure on 1 June 1979.