Félix Dujardin (5 April 1801 – 8 April 1860) was a French

biologist A biologist is a scientist who conducts research in biology. Biologists are interested in studying life on Earth, whether it is an individual Cell (biology), cell, a multicellular organism, or a Community (ecology), community of Biological inter ...

born in

Tours Tours ( ; ) is the largest city in the region of Centre-Val de Loire, France. It is the Prefectures in France, prefecture of the Departments of France, department of Indre-et-Loire. The Communes of France, commune of Tours had 136,463 inhabita ...

. He is remembered for his research on

protozoans Protozoa (: protozoan or protozoon; alternative plural: protozoans) are a polyphyletic group of single-celled eukaryotes, either free-living or parasitic, that feed on organic matter such as other microorganisms or organic debris. Historically ...

and other

invertebrates Invertebrates are animals that neither develop nor retain a vertebral column (commonly known as a ''spine'' or ''backbone''), which evolved from the notochord. It is a paraphyletic grouping including all animals excluding the chordate subphylum ...

Biography

In 1840 Dujardin was appointed professor of

geology Geology (). is a branch of natural science concerned with the Earth and other astronomical objects, the rocks of which they are composed, and the processes by which they change over time. Modern geology significantly overlaps all other Earth ...

and

mineralogy Mineralogy is a subject of geology specializing in the scientific study of the chemistry, crystal structure, and physical (including optical mineralogy, optical) properties of minerals and mineralized artifact (archaeology), artifacts. Specific s ...

at the

University of Toulouse The University of Toulouse (, ) is a community of universities and establishments ( ComUE) based in Toulouse, France. Originally it was established in 1229, making it one of the earliest universities to emerge in Europe. Suppressed during the ...

, and during the following year was a professor of

zoology Zoology ( , ) is the scientific study of animals. Its studies include the anatomy, structure, embryology, Biological classification, classification, Ethology, habits, and distribution of all animals, both living and extinction, extinct, and ...

and

botany Botany, also called plant science, is the branch of natural science and biology studying plants, especially Plant anatomy, their anatomy, Plant taxonomy, taxonomy, and Plant ecology, ecology. A botanist or plant scientist is a scientist who s ...

Rennes Rennes (; ; Gallo language, Gallo: ''Resnn''; ) is a city in the east of Brittany in Northwestern France at the confluence of the rivers Ille and Vilaine. Rennes is the prefecture of the Brittany (administrative region), Brittany Regions of F ...

. In regard to his educational background, Dujardin was largely self-taught, the son of a watchmaker. Dujardin worked with microscopic animal life, and in 1834 proposed that a new group of one-celled organisms be called Rhizopoda. He denied

naturalist Natural history is a domain of inquiry involving organisms, including animals, fungi, and plants, in their natural environment, leaning more towards observational than experimental methods of study. A person who studies natural history is cal ...

Christian Gottfried Ehrenberg Christian Gottfried Ehrenberg (19 April 1795 – 27 June 1876) was a German Natural history, naturalist, zoologist, Botany, botanist, comparative anatomist, geologist, and microscopy, microscopist. He is considered to be one of the most famous an ...

's theory that microscopic organisms were "complete organisms" similar to higher animals, specifically noting that they had specialized structures unique to single-celled organisms, which meant that the foraminiferan he was studying was not, as his contemporaries believed it to be, a mollusc. In addition to his studies of microscopic life, he did extensive research on invertebrate groups that included

echinoderm An echinoderm () is any animal of the phylum Echinodermata (), which includes starfish, brittle stars, sea urchins, sand dollars and sea cucumbers, as well as the sessile sea lilies or "stone lilies". While bilaterally symmetrical as ...

s, hexapods, helminths and

cnidarian Cnidaria ( ) is a phylum under kingdom Animalia containing over 11,000 species of aquatic invertebrates found both in fresh water, freshwater and marine environments (predominantly the latter), including jellyfish, hydroid (zoology), hydroids, ...

s. In the

Foraminifera Foraminifera ( ; Latin for "hole bearers"; informally called "forams") are unicellular organism, single-celled organisms, members of a phylum or class (biology), class of Rhizarian protists characterized by streaming granular Ectoplasm (cell bio ...

, he noticed an apparently formless life substance that he named "sarcode", later renamed

protoplasm Protoplasm (; ) is the part of a cell that is surrounded by a plasma membrane. It is a mixture of small molecules such as ions, monosaccharides, amino acids, and macromolecules such as proteins, polysaccharides, lipids, etc. In some definitions ...

by Hugo von Mohl (1805–1872). Dujardin remains famous for the naming, identification and the first description in 1850 of the

mushroom bodies The mushroom bodies or ''corpora pedunculata'' are a pair of structures in the Supraesophageal ganglion, brain of arthropods, including insects and Crustacean, crustaceans, and some annelids (notably the ragworm ''Platynereis dumerilii''). They a ...

(''corpora pedunculata'')Dujardin, F. 1850. ''Mémoire sur le système nerveux des insectes''. Ann. Sci. Nat. Zool. 14: 195-206. in the hymenopteran

brain The brain is an organ (biology), organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It consists of nervous tissue and is typically located in the head (cephalization), usually near organs for ...

( bee,

bumblebee A bumblebee (or bumble bee, bumble-bee, or humble-bee) is any of over 250 species in the genus ''Bombus'', part of Apidae, one of the bee families. This genus is the only Extant taxon, extant group in the tribe Bombini, though a few extinct r ...

, sphex,

ant Ants are Eusociality, eusocial insects of the Family (biology), family Formicidae and, along with the related wasps and bees, belong to the Taxonomy (biology), order Hymenoptera. Ants evolved from Vespoidea, vespoid wasp ancestors in the Cre ...

, fruitfly ''

Drosophila melanogaster ''Drosophila melanogaster'' is a species of fly (an insect of the Order (biology), order Diptera) in the family Drosophilidae. The species is often referred to as the fruit fly or lesser fruit fly, or less commonly the "vinegar fly", "pomace fly" ...

'', etc.), which he postulated for the first time were the site of intelligence - he wrote that bees have "memories of places and things". This major discovery proved to be significant, as these structures are now considered the place where

memory Memory is the faculty of the mind by which data or information is encoded, stored, and retrieved when needed. It is the retention of information over time for the purpose of influencing future action. If past events could not be remembe ...

and many other behaviors are formed and processed in

. He suggested that one sign of honey bees' intelligence was their communication about flower locations, seventy-seven years before

Karl von Frisch Karl Ritter von Frisch, (20 November 1886 – 12 June 1982) was a German-Austrian ethology, ethologist who received the Nobel Prize in Physiology or Medicine in 1973, along with Nikolaas Tinbergen and Konrad Lorenz. His work centered on investi ...

's 'waggle dance' theory was published. In addition, he valued the importance of brain-to-body-mass ratio and the relative sizes of brain parts to the whole instead of comparing absolute sizes, over a century before it became current thinking.

Honours and distinctions

In 1840, Louis Michel François Doyère named the

tardigrade Tardigrades (), known colloquially as water bears or moss piglets, are a phylum of eight-legged segmented micro-animals. They were first described by the German zoologist Johann August Ephraim Goeze in 1773, who called them . In 1776, th ...

'' Macrobiotus dujardini'' in his honour.

Bibliography

* Dujardin F. 1837
''Mémoire sur les couches du sol en Touraine et descriptions des coquilles de la craie des faluns''
. * Dujardin F. 1841
''Histoire naturelle des zoophytes. Infusoires, comprenant la physiologie et la classification de ces animaux, et la manière de les étudier à l'aide du microscope''
* Dujardin F. 1842
''Nouveau manuel de l'observateur au microscope''
* Dujardin F. 1845
''Histoire naturelle des helminthes ou vers intestinaux''
xvi, 654+15 pp.
Plates
* Dujardin F. 1850. ''Mémoire sur le système nerveux des insectes''. Ann. Sci. Nat. Zool. 14: 195-206. The standard author abbreviation Dujard is applied to

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

he described.

References

External sources

''Félix Dujardin''
@

Encyclopædia Britannica Online An encyclopedia is a reference work or compendium providing summaries of knowledge, either general or special, in a particular field or discipline. Encyclopedias are divided into articles or entries that are arranged alphabetically by artic ...

''article on Felix Dujardin's Contributions to Protistology''
{{DEFAULTSORT:Dujardin, Félix 19th-century French biologists 1801 births 1860 deaths French parasitologists Scientists from Tours, France French zoologists Academic staff of the University of Toulouse

Biography

Honours and distinctions

Bibliography

References

Further reading

External sources