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 one of the largest cities 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 ...

. He is remembered for his research on

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

and other

invertebrates Invertebrates are a paraphyletic group of animals that neither possess nor develop a vertebral column (commonly known as a ''backbone'' or ''spine''), derived from the notochord. This is a grouping including all animals apart from the chordate ...

Biography

In 1840 he was appointed professor of

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

and

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

at the

University of Toulouse The University of Toulouse (french: Université de Toulouse) was a university in the French city of Toulouse that was established by papal bull in 1229, making it one of the earliest universities to emerge in Europe. Suppressed during the Frenc ...

, and during the following year was a professor of

zoology Zoology ()The pronunciation of zoology as is usually regarded as nonstandard, though it is not uncommon. is the branch of biology that studies the Animal, animal kingdom, including the anatomy, structure, embryology, evolution, Biological clas ...

and

botany Botany, also called , plant biology or phytology, is the science of plant life and a branch of biology. A botanist, plant scientist or phytologist is a scientist who specialises in this field. The term "botany" comes from the Ancient Greek w ...

Rennes Rennes (; br, Roazhon ; Gallo: ''Resnn''; ) is a city in the east of Brittany in northwestern France at the confluence of the Ille and the Vilaine. Rennes is the prefecture of the region of Brittany, as well as the Ille-et-Vilaine department ...

. 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 An amoeba (; less commonly spelled ameba or amœba; plural ''am(o)ebas'' or ''am(o)ebae'' ), often called an amoeboid, is a type of Cell (biology), cell or unicellular organism with the ability to alter its shape, primarily by extending and ret ...

. He denied naturalist

Christian Gottfried Ehrenberg Christian Gottfried Ehrenberg (19 April 1795 – 27 June 1876) was a German naturalist, zoologist, comparative anatomist, geologist, and microscopist. Ehrenberg was an evangelist and was considered to be of the most famous and productive scie ...

'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 foraminifera he was studying was not, as his contemporaries believed it to be, a mollusk. In addition to his studies of microscopic life, he did extensive research on invertebrate groups that included

echinoderm An echinoderm () is any member of the phylum Echinodermata (). The adults are recognisable by their (usually five-point) radial symmetry, and include starfish, brittle stars, sea urchins, sand dollars, and sea cucumbers, as well as the sea ...

s, hexapods,

helminth Parasitic worms, also known as helminths, are large macroparasites; adults can generally be seen with the naked eye. Many are intestinal worms that are soil-transmitted and infect the gastrointestinal tract. Other parasitic worms such as schi ...

s and cnidarians. In the

Foraminifera Foraminifera (; Latin for "hole bearers"; informally called "forams") are single-celled organisms, members of a phylum or class of amoeboid protists characterized by streaming granular Ectoplasm (cell biology), ectoplasm for catching food and ot ...

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

Hugo von Mohl Hugo von Mohl FFRS H FRSE (8 April 1805 – 1 April 1872) was a German botanist from Stuttgart. He was the first person to use the word " protoplasm". Life He was a son of the Württemberg statesman Benjamin Ferdinand von Mohl (1766–18 ...

(1805–1872). Dujardin also remains famous for the identification and the first description in 1850 of the

mushroom bodies The mushroom bodies or ''corpora pedunculata'' are a pair of structures in the brain of insects, other arthropods, and some annelids (notably the ragworm ''Platynereis dumerilii''). They are known to play a role in olfactory learning and memory ...

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

brain A brain is an organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It is located in the head, usually close to the sensory organs for senses such as vision. It is the most complex organ in a v ...

( 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 group in the tribe Bombini, though a few extinct related gener ...

sphex Wasps of the genus ''Sphex'' (commonly known as digger wasps) are cosmopolitan predators that sting and paralyze prey insects. ''Sphex'' is one of many genera in the old digger wasp family Sphecidae ('' sensu lato''), though most apart from the ...

ant Ants are eusocial insects of the family Formicidae and, along with the related wasps and bees, belong to the order Hymenoptera. Ants evolved from vespoid wasp ancestors in the Cretaceous period. More than 13,800 of an estimated total of 22 ...

, fruitfly ''

Drosophila melanogaster ''Drosophila melanogaster'' is a species of fly (the taxonomic 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" or "pomace fly". Starting with Ch ...

'', etc.), which he postulated for the first time that they were the site of intelligence. This major discovery will eventually prove to be almost accurate, 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 remembered, ...

and many other behaviors are formed and processed in

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 In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

he described.

References

* Louis Joubin, 1901, ''Félix Dujardin, 1801-1860''. Archives de Parasitologie, Volume 4, 5-60
PDF
*

External sources

''Félix Dujardin''
@

Encyclopædia Britannica Online An encyclopedia (American English) or encyclopædia (British English) is a reference work or compendium providing summaries of knowledge either general or special to a particular field or discipline. Encyclopedias are divided into article ...

''article on Felix Dujardin's Contributions to Protistology''
{{Authority control French biologists 1801 births 1860 deaths French parasitologists Scientists from Tours, France French zoologists University of Toulouse faculty