Pierre-Paul Grassé
Encyclopedia
Pierre-Paul Grassé, born on November 27, 1895 in Périgueux
(Dordogne
) and died on July 9, 1985, was a French zoologist, author of over 300 publications including the influential 35-volume Traité de Zoologie
. He was an expert on termites.
at the University of Bordeaux
and studied Natural science
in parallel, including the lectures of the entomologist Jean de Feytaud (1881–1973). Mobilized during World War I
, he was forced to interrupt his studies during four years. By the end of the war he was a military surgeon.
He continued his studies in Paris, focusing exclusively on science. He obtained his Licence and frequents the laboratory of Étienne Rabaud (1868–1956). Il abandoned his preparations for the agrégation
to accept a position as professor in the École Nationale Supérieure Agronomique de Montpellier
(1921), where the department of zoology is led by François Picard
(1879–1939). There he frequented several phytogeographers
like Charles Flahault
(1852–1935), Josias Braun-Blanquet
(1884–1980), Georges Kuhnholtz-Lordat (1888–1965) and Marie Louis Emberger (1897–1969). He became the assistant of Octave Duboscq (1868–1943) who orients the young Grassé towards the study of protozoan parasites. After the departure of Duboscq to Paris, Grassé worked for pour Eugène Bataillon (1864–1953) and there discovered techniques for experimental embryology.
In 1926, he became vice-director of the École supérieure de sériciculture
. He submitted his theses, Contribution à l'étude des flagellés parasites, in 1926, and it was published in the Archives de zoologie expérimentale et générale.
. He supervised the theses of several students on insect
s. He conducted his first field research trip in Africa in 1933-1934, and returned there several times (1938–1939, 1945, 1948). During these trips he studied termite
s, and became one of the great specialists on these insects.
In 1935, he became an Assistant Professor at the Université de Paris where he works alongside Germaine Cousin
(1896–1992), and received the Prix Gadeau de Kerville de la Société entomologique de France for his work on orthoptera
and termites. In 1939 he chaired the Société zoologique de France
and in 1941 the Société entomologique de France
.
After having been briefly mobilized in Tours
, in 1944 he succeeded Maurice Caullery
as Chair in Zoology and the Evolution of Beings. Grassé was elected a member of the Académie des sciences on November 29, 1948, in the anatomy and zoology sector and presided over the institution in 1967. In 1976 he changed sectors, into the newly created animal and vegetal biology sector.
Grassé received numerous honours and titles during his career: commander of the Légion d'honneur
, doctor honoris causa of the universities of Brussels
, Basel
, Bonn
, Ghent
, Madrid
, Barcelona
and São Paulo
. He was also a member of several academic societies, including the New York Academy of Sciences
, The Royal Academies for Science and the Arts of Belgium
, etc.
. The 38 volumes required almost forty years of work, uniting some of the greatest names in zoology. They are still essential references in the field for the groups that are treated in their pages. Ten volumes are dedicated to mammals, nine to insects. Apart from this treatise, he led two collections published by Masson
: the first, entitled Grands problèmes de la biologie, has thirteen volumes and the second is entitled Précis de sciences biologiques. Alongside Andrée Tétry, he composed the two volumes dedicated to zoology in the collection Bibliothèque de la Pléiade
, published by Gallimard. He also supervised the edition of the Abrégé de zoologie (two volumes, Masson).
He also composed the Termitologia (1982, 1983, 1984), a work in three volumes totalling over 2400 pages. In it Grassé compiles all available knowledge concerning termites. It was by studying symbiotic flagellates in termites that he eventually began studying their hosts. In this publication, Grassé introduced the concept of Stigmergy
:
He also created three scientific reviews: Arvernia biologica (1932), Insectes sociaux (1953) et Biologia gabonica (1964). He participated in several reviews like the Annales des sciences naturelles and the Bulletin biologique de la France et de la Belgique. Apart from his numerous scientific publications, he published several works popularising science such as La Vie des animaux (Larousse
, 1968). Il also signed the articles "Évolution" and "Stigmergie" of the Encyclopædia Universalis
.
Grassé also authored many works where he talks of his views on evolution
and metaphysics
such as Toi, ce petit Dieu (Albin Michel, 1971), L’Évolution du vivant, matériaux pour une nouvelle théorie transformiste (Albin Michel, 1973), La Défaite de l’amour ou le triomphe de Freud (Albin Michel, 1976), Biologie moléculaire, mutagenèse et évolution (Masson, 1978), L’Homme en accusation: de la biologie à la politique (Albin Michel, 1980)...
. He occupied the Chair of Evolutionary Biology of the Faculty of Paris, of which the two previous occupiers, Alfred Giard (1846–1908) and Maurice Caullery
(1868–1958), were both also supporters of lamarckism. Only after Grassé's retirement did the chair become occupied by a partisan of Darwinism, Charles Bocquet (1918–1977).
In support of Lamarck's theories he organised an international congress in Paris in 1947 under the auspices of the CNRS with the theme "paleontology and transformism". The records were published in 1950 by Albin Michel. He united many of the greatest French authorities on the question: Lucien Cuénot
(1866–1951), Pierre Teilhard de Chardin
(1881–1955), Maurice Caullery.... They were all opponents to certain tenets of neo-darwinism
. Other brilliant biologists present were John Burdon Sanderson Haldane (1892–1964) and George Gaylord Simpson
(1902–1984). Grassé stated his support for Lamarck in other ways too, like an article in the Encyclopædia Universalis
, and by affirming that Lamarck had been unjustifiably slandered and ought to be rehabilitated.
Grassé presents his arguments against Darwinism
in his work L'évolution du vivant (1973). Against the idea which states that the evolution of living things is the product of their adaptating to changes in their environments, he opposes living fossil
s, meaning species which stopped evolving at some point in time and have remained relatively identical to this day regardless of great climatic or geological changes (he cites numerous examples in Les formes panchroniques et les arrêts de l'évolution, p. 133). Therefore, evolution is in his opinion a process which is not necessary, it does not occur in living beings under the constraints of external physical forces (cf. Necessity-utility is not the primus movens of biological evolution, p. 302). To explain evolution he instead thinks that you must look at the internal dynamics of living things.
Some authors, like Marcel Blanc, explain the strong support of Lamarck by French biologists by giving simple patriotic reasons and the historical and social context: Catholic culture favoring support of Lamarckism whilst Protestant culture favored support of Darwinism, although, Grassé was a Protestant.
Périgueux
Périgueux is a commune in the Dordogne department in Aquitaine in southwestern France.Périgueux is the prefecture of the department and the capital of the region...
(Dordogne
Dordogne
Dordogne is a départment in south-west France. The départment is located in the region of Aquitaine, between the Loire valley and the High Pyrénées named after the great river Dordogne that runs through it...
) and died on July 9, 1985, was a French zoologist, author of over 300 publications including the influential 35-volume Traité de Zoologie
Traite de Zoologie
The , complete title popularly known as is a 52 volume synthesis of Zoology published between 1950 and 1979 originally under the direction of Pierre-Paul Grassé. A new edition commenced in 1980. The books were not published in order, and some promised parts are yet to appear. The books are...
. He was an expert on termites.
Studies
He began his studies in Périgueux where his parents owned a small business. He went on to study medicineMedicine
Medicine is the science and art of healing. It encompasses a variety of health care practices evolved to maintain and restore health by the prevention and treatment of illness....
at the University of Bordeaux
University of Bordeaux
University of Bordeaux is an association of higher education institutions in and around Bordeaux, France. Its current incarnation was established 21 March 2007. The group is the largest system of higher education schools in southwestern France. It is part of the Academy of Bordeaux.There are seven...
and studied Natural science
Natural science
The natural sciences are branches of science that seek to elucidate the rules that govern the natural world by using empirical and scientific methods...
in parallel, including the lectures of the entomologist Jean de Feytaud (1881–1973). Mobilized during World War I
World War I
World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...
, he was forced to interrupt his studies during four years. By the end of the war he was a military surgeon.
He continued his studies in Paris, focusing exclusively on science. He obtained his Licence and frequents the laboratory of Étienne Rabaud (1868–1956). Il abandoned his preparations for the agrégation
Agrégation
In France, the agrégation is a civil service competitive examination for some positions in the public education system. The laureates are known as agrégés...
to accept a position as professor in the École Nationale Supérieure Agronomique de Montpellier
Montpellier
-Neighbourhoods:Since 2001, Montpellier has been divided into seven official neighbourhoods, themselves divided into sub-neighbourhoods. Each of them possesses a neighbourhood council....
(1921), where the department of zoology is led by François Picard
François Picard
François Picard was a racing driver from France. He participated in one Formula One Grand Prix, on 19 October 1958. He scored no championship points. This race was his last, as he crashed his Cooper into Olivier Gendebien's Ferrari, which had spun in front of him, and Picard suffered serious...
(1879–1939). There he frequented several phytogeographers
Phytogeography
Phytogeography , also called geobotany, is the branch of biogeography that is concerned with the geographic distribution of plant species...
like Charles Flahault
Charles Flahault
Charles Henri Marie Flahault was a French botanist, among the early pioneers of phytogeography, phytosociology and forest ecology...
(1852–1935), Josias Braun-Blanquet
Josias Braun-Blanquet
Josias Braun-Blanquet was an influential phytosociologist and botanist. Braun-Blanquet was born in Chur, Switzerland and died in Montpellier, France.-Phytosociology:...
(1884–1980), Georges Kuhnholtz-Lordat (1888–1965) and Marie Louis Emberger (1897–1969). He became the assistant of Octave Duboscq (1868–1943) who orients the young Grassé towards the study of protozoan parasites. After the departure of Duboscq to Paris, Grassé worked for pour Eugène Bataillon (1864–1953) and there discovered techniques for experimental embryology.
In 1926, he became vice-director of the École supérieure de sériciculture
Sericulture
Sericulture, or silk farming, is the rearing of silkworms for the production of raw silk.Although there are several commercial species of silkworms, Bombyx mori is the most widely used and intensively studied. According to Confucian texts, the discovery of silk production by B...
. He submitted his theses, Contribution à l'étude des flagellés parasites, in 1926, and it was published in the Archives de zoologie expérimentale et générale.
Teaching and research
In 1929, he became professor of zoologie at the Université de Clermont-FerrandClermont-Ferrand
Clermont-Ferrand is a city and commune of France, in the Auvergne region, with a population of 140,700 . Its metropolitan area had 409,558 inhabitants at the 1999 census. It is the prefecture of the Puy-de-Dôme department...
. He supervised the theses of several students on insect
Insect
Insects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...
s. He conducted his first field research trip in Africa in 1933-1934, and returned there several times (1938–1939, 1945, 1948). During these trips he studied termite
Termite
Termites are a group of eusocial insects that, until recently, were classified at the taxonomic rank of order Isoptera , but are now accepted as the epifamily Termitoidae, of the cockroach order Blattodea...
s, and became one of the great specialists on these insects.
In 1935, he became an Assistant Professor at the Université de Paris where he works alongside Germaine Cousin
Germaine Cousin
Saint Germaine Cousin is a French saint. She was born in 1579 of humble parents at Pibrac, a village about ten miles from Toulouse.Of her, the Catholic Encyclopedia writes:...
(1896–1992), and received the Prix Gadeau de Kerville de la Société entomologique de France for his work on orthoptera
Orthoptera
Orthoptera is an order of insects with paurometabolous or incomplete metamorphosis, including the grasshoppers, crickets and locusts.Many insects in this order produce sound by rubbing their wings against each other or their legs, the wings or legs containing rows of corrugated bumps...
and termites. In 1939 he chaired the Société zoologique de France
Société zoologique de France
La Société zoologique de France or Zoological Society of France is a scientific society devoted to Zoology. It was founded in 1876....
and in 1941 the Société entomologique de France
Société entomologique de France
The Société entomologique de France, or French Entomological Society, is devoted to the study of insects. It was founded in 1832.The society was created by eighteen Parisian entomologists on January 31, 1832...
.
After having been briefly mobilized in Tours
Tours
Tours is a city in central France, the capital of the Indre-et-Loire department.It is located on the lower reaches of the river Loire, between Orléans and the Atlantic coast. Touraine, the region around Tours, is known for its wines, the alleged perfection of its local spoken French, and for the...
, in 1944 he succeeded Maurice Caullery
Maurice Caullery
Maurice Jules Gaston Corneille Caullery , Paris) was a French biologist.Caullery specialised in parasitic protozoans and marine invertebrates. He also worked on insects.-Awards:...
as Chair in Zoology and the Evolution of Beings. Grassé was elected a member of the Académie des sciences on November 29, 1948, in the anatomy and zoology sector and presided over the institution in 1967. In 1976 he changed sectors, into the newly created animal and vegetal biology sector.
Grassé received numerous honours and titles during his career: commander of the Légion d'honneur
Légion d'honneur
The Legion of Honour, or in full the National Order of the Legion of Honour is a French order established by Napoleon Bonaparte, First Consul of the Consulat which succeeded to the First Republic, on 19 May 1802...
, doctor honoris causa of the universities of Brussels
Université Libre de Bruxelles
The Université libre de Bruxelles is a French-speaking university in Brussels, Belgium. It has 21,000 students, 29% of whom come from abroad, and an equally cosmopolitan staff.-Name:...
, Basel
University of Basel
The University of Basel is located in Basel, Switzerland, and is considered to be one of leading universities in the country...
, Bonn
University of Bonn
The University of Bonn is a public research university located in Bonn, Germany. Founded in its present form in 1818, as the linear successor of earlier academic institutions, the University of Bonn is today one of the leading universities in Germany. The University of Bonn offers a large number...
, Ghent
Ghent University
Ghent University is a Dutch-speaking public university located in Ghent, Belgium. It is one of the larger Flemish universities, consisting of 32,000 students and 7,100 staff members. The current rector is Paul Van Cauwenberge.It was established in 1817 by King William I of the Netherlands...
, Madrid
Complutense University of Madrid
The Complutense University of Madrid is a university in Madrid, and one of the oldest universities in the world. It is located on a sprawling campus that occupies the entirety of the Ciudad Universitaria district of Madrid, with annexes in the district of Somosaguas in the neighboring city of...
, Barcelona
University of Barcelona
The University of Barcelona is a public university located in the city of Barcelona, Catalonia in Spain. It is a member of the Coimbra Group, LERU, European University Association, Mediterranean Universities Union, International Research Universities Network and Vives Network...
and São Paulo
University of São Paulo
Universidade de São Paulo is a public university in the Brazilian state of São Paulo. It is the largest Brazilian university and one of the country's most prestigious...
. He was also a member of several academic societies, including the New York Academy of Sciences
New York Academy of Sciences
The New York Academy of Sciences is the third oldest scientific society in the United States. An independent, non-profit organization with more than members in 140 countries, the Academy’s mission is to advance understanding of science and technology...
, The Royal Academies for Science and the Arts of Belgium
The Royal Academies for Science and the Arts of Belgium
There are two Royal Academies for Science and the Arts in Belgium, corresponding to the two main languages of the country, Dutch and French . The Academies are located in the Palace of Academies in Brussels....
, etc.
Publications
Grassé began publishing a very big project in 1946 intitled Traité de zoologieTraite de Zoologie
The , complete title popularly known as is a 52 volume synthesis of Zoology published between 1950 and 1979 originally under the direction of Pierre-Paul Grassé. A new edition commenced in 1980. The books were not published in order, and some promised parts are yet to appear. The books are...
. The 38 volumes required almost forty years of work, uniting some of the greatest names in zoology. They are still essential references in the field for the groups that are treated in their pages. Ten volumes are dedicated to mammals, nine to insects. Apart from this treatise, he led two collections published by Masson
Masson (publisher)
Masson was a French publisher specialised in medical and scientific collections. In 1987, Masson purchased Armand Colin. In turn, it became part of the City Group in 1994...
: the first, entitled Grands problèmes de la biologie, has thirteen volumes and the second is entitled Précis de sciences biologiques. Alongside Andrée Tétry, he composed the two volumes dedicated to zoology in the collection Bibliothèque de la Pléiade
Bibliothèque de la Pléiade
The Bibliothèque de la Pléiade is a French series of books which was created in the 1930s by Jacques Schiffrin, an independent young editor. . Schiffrin wanted to provide the public with reference editions of the complete works of classic authors in a pocket format...
, published by Gallimard. He also supervised the edition of the Abrégé de zoologie (two volumes, Masson).
He also composed the Termitologia (1982, 1983, 1984), a work in three volumes totalling over 2400 pages. In it Grassé compiles all available knowledge concerning termites. It was by studying symbiotic flagellates in termites that he eventually began studying their hosts. In this publication, Grassé introduced the concept of Stigmergy
Stigmergy
Stigmergy is a mechanism of indirect coordination between agents or actions. The principle is that the trace left in the environment by an action stimulates the performance of a next action, by the same or a different agent...
:
- "Stigmergy manifests itself in the termite mound by the fact that the individual labour of each construction worker stimulates and guides the work of its neighbour.".
He also created three scientific reviews: Arvernia biologica (1932), Insectes sociaux (1953) et Biologia gabonica (1964). He participated in several reviews like the Annales des sciences naturelles and the Bulletin biologique de la France et de la Belgique. Apart from his numerous scientific publications, he published several works popularising science such as La Vie des animaux (Larousse
Éditions Larousse
Éditions Larousse is a French publishing house specialising in reference works such as dictionaries. It was founded by Pierre Larousse and its best-known work is the Petit Larousse.It was acquired by Vivendi Universal in 1998...
, 1968). Il also signed the articles "Évolution" and "Stigmergie" of the Encyclopædia Universalis
Encyclopædia Universalis
The Encyclopædia Universalis is a French-language general encyclopedia published by Encyclopædia Britannica, Inc., a privately held company. The articles of the Encyclopædia Universalis are aimed at educated adult readers, and written by a staff of full-time editors and expert contributors...
.
Grassé also authored many works where he talks of his views on evolution
Evolution
Evolution is any change across successive generations in the heritable characteristics of biological populations. Evolutionary processes give rise to diversity at every level of biological organisation, including species, individual organisms and molecules such as DNA and proteins.Life on Earth...
and metaphysics
Metaphysics
Metaphysics is a branch of philosophy concerned with explaining the fundamental nature of being and the world, although the term is not easily defined. Traditionally, metaphysics attempts to answer two basic questions in the broadest possible terms:...
such as Toi, ce petit Dieu (Albin Michel, 1971), L’Évolution du vivant, matériaux pour une nouvelle théorie transformiste (Albin Michel, 1973), La Défaite de l’amour ou le triomphe de Freud (Albin Michel, 1976), Biologie moléculaire, mutagenèse et évolution (Masson, 1978), L’Homme en accusation: de la biologie à la politique (Albin Michel, 1980)...
Neo-lamarckism in France
Grassé was a supporter of the French tradition of LamarckismLamarckism
Lamarckism is the idea that an organism can pass on characteristics that it acquired during its lifetime to its offspring . It is named after the French biologist Jean-Baptiste Lamarck , who incorporated the action of soft inheritance into his evolutionary theories...
. He occupied the Chair of Evolutionary Biology of the Faculty of Paris, of which the two previous occupiers, Alfred Giard (1846–1908) and Maurice Caullery
Maurice Caullery
Maurice Jules Gaston Corneille Caullery , Paris) was a French biologist.Caullery specialised in parasitic protozoans and marine invertebrates. He also worked on insects.-Awards:...
(1868–1958), were both also supporters of lamarckism. Only after Grassé's retirement did the chair become occupied by a partisan of Darwinism, Charles Bocquet (1918–1977).
In support of Lamarck's theories he organised an international congress in Paris in 1947 under the auspices of the CNRS with the theme "paleontology and transformism". The records were published in 1950 by Albin Michel. He united many of the greatest French authorities on the question: Lucien Cuénot
Lucien Cuenot
Lucien Cuénot was a French biologist. In the first half of the 20th century, Mendelism was not a popular subject among French biologists. Cuénot defied popular opinion and shirked the “pseudo-sciences” as he called them...
(1866–1951), Pierre Teilhard de Chardin
Pierre Teilhard de Chardin
Pierre Teilhard de Chardin SJ was a French philosopher and Jesuit priest who trained as a paleontologist and geologist and took part in the discovery of both Piltdown Man and Peking Man. Teilhard conceived the idea of the Omega Point and developed Vladimir Vernadsky's concept of Noosphere...
(1881–1955), Maurice Caullery.... They were all opponents to certain tenets of neo-darwinism
Neo-Darwinism
Neo-Darwinism is the 'modern synthesis' of Darwinian evolution through natural selection with Mendelian genetics, the latter being a set of primary tenets specifying that evolution involves the transmission of characteristics from parent to child through the mechanism of genetic transfer, rather...
. Other brilliant biologists present were John Burdon Sanderson Haldane (1892–1964) and George Gaylord Simpson
George Gaylord Simpson
George Gaylord Simpson was an American paleontologist. Simpson was perhaps the most influential paleontologist of the twentieth century, and a major participant in the modern evolutionary synthesis, contributing Tempo and mode in evolution , The meaning of evolution and The major features of...
(1902–1984). Grassé stated his support for Lamarck in other ways too, like an article in the Encyclopædia Universalis
Encyclopædia Universalis
The Encyclopædia Universalis is a French-language general encyclopedia published by Encyclopædia Britannica, Inc., a privately held company. The articles of the Encyclopædia Universalis are aimed at educated adult readers, and written by a staff of full-time editors and expert contributors...
, and by affirming that Lamarck had been unjustifiably slandered and ought to be rehabilitated.
Grassé presents his arguments against Darwinism
Darwinism
Darwinism is a set of movements and concepts related to ideas of transmutation of species or of evolution, including some ideas with no connection to the work of Charles Darwin....
in his work L'évolution du vivant (1973). Against the idea which states that the evolution of living things is the product of their adaptating to changes in their environments, he opposes living fossil
Living fossil
Living fossil is an informal term for any living species which appears similar to a species otherwise only known from fossils and which has no close living relatives, or a group of organisms which have long fossil records...
s, meaning species which stopped evolving at some point in time and have remained relatively identical to this day regardless of great climatic or geological changes (he cites numerous examples in Les formes panchroniques et les arrêts de l'évolution, p. 133). Therefore, evolution is in his opinion a process which is not necessary, it does not occur in living beings under the constraints of external physical forces (cf. Necessity-utility is not the primus movens of biological evolution, p. 302). To explain evolution he instead thinks that you must look at the internal dynamics of living things.
Some authors, like Marcel Blanc, explain the strong support of Lamarck by French biologists by giving simple patriotic reasons and the historical and social context: Catholic culture favoring support of Lamarckism whilst Protestant culture favored support of Darwinism, although, Grassé was a Protestant.
Works
Partial List- 1935: Parasites et parasitisme, Armand Collin (Paris) : 224 p..
- 1935: with Max Aron (1892–1974), Précis de biologie animale, Masson (Paris) : viii + 1016 p. – second revised edition in 1939, third edition in 1947, fourth edition in 1948, fifth edition in 1957, sixth edition in 1962, eighth edition in 1966.
- 1963: with A. Tétry, Zoologie, two volumes, Gallimard (Paris), collection encyclopédie de la Pléiade: xx + 1244 p. et xvi + 1040 p.
- 1971: Toi, ce petit dieu ! essai sur l'histoire naturelle de l'homme, Albin Michel (Paris) : 288 p.
- 1973: L'évolution du vivant, matériaux pour une nouvelle théorie transformiste, Albin Michel (Paris) : 477 p.
- 1978: Biologie moléculaire, mutagenèse et évolution, Masson (Paris) : 117 p. ISBN 2-225-49203-4
- 1980: L'Homme en accusation : de la biologie à la politique, Albin Michel (Paris) : 354 p. ISBN 2-226-01054-8
- 1982-1986: Termitologia. Vol. I: Anatomie Physilogie Reproduction, 676 pp.; Vol. II: Fondation des Sociétés Construction, 613 pp.; Vol. III: Comportement Socialité Écologie Évolution Systématique, 715 pp. Paris: Masson.
Sources
- Paul Pesson (1985). Hommage à Pierre-Paul Grassé (1895–1985), Professeur honoraire à l’Université de Paris, Membre de l’Académie des Sciences, Bulletin de la Société entomologique de France, 90 (9-10) : i-vii.
- Jean Lhoste (1987). Les Entomologistes français. 1750-1950, INRA Éditions et OPIE : 351 p. [244-247]
External links
- Stigmergy: Invisible Writing, Collective Intelligence in Social Insects in Introduction & Self-Organisation by David Gordon for the AI depot.
- Stigmergic Collaboration: A Theoretical Framework for Mass Collaboration by : Elliott, Dr Mark Alan (2007) PhD thesis, Centre for Ideas, Victorian College of the Arts, University of Melbourne. The thesis explicitly refers to the work of Pierre-Paul Grassé to define stigmergy, chapter 3.