Félix Dujardin (5 April 1801 – 8 April 1860) was a French biologist born in Tours. 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. Hist ...

and other invertebrates.

Biography

In 1840 he was appointed professor of

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

and mineralogy at the University of Toulouse, 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 kingdom, including the structure, embryology, evolution, classification, habits, an ...

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 ...

at Rennes. 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

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 scient ...

'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 ...

s, hexapods, helminths 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 for catching food and other uses; and commonly ...

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

Hugo von Mohl Hugo von Mohl FFRS HFRSE (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 (1766–1845), ...

(1805–1872). Dujardin also remains famous for the identification and the first description in 1850 of the mushroom bodies (''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 (biology), 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 Visual perception, vision. I ...

(

bee Bees are winged insects closely related to wasps and ants, known for their roles in pollination and, in the case of the best-known bee species, the western honey bee, for producing honey. Bees are a monophyletic lineage within the superfami ...

, bumblebee, sphex, ant, fruitfly '' Drosophila melanogaster'', 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 remember ...

and many other behaviors are formed and processed in invertebrates.

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 appropriat ...

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