John Hogg (1800–1869) was a British naturalist who wrote about

amphibians Amphibians are ectothermic, anamniote, anamniotic, tetrapod, four-limbed vertebrate animals that constitute the class (biology), class Amphibia. In its broadest sense, it is a paraphyletic group encompassing all Tetrapod, tetrapods, but excl ...

, birds, plants,

reptile Reptiles, as commonly defined, are a group of tetrapods with an ectothermic metabolism and Amniotic egg, amniotic development. Living traditional reptiles comprise four Order (biology), orders: Testudines, Crocodilia, Squamata, and Rhynchocepha ...

s, and

protist A protist ( ) or protoctist is any eukaryotic organism that is not an animal, land plant, or fungus. Protists do not form a natural group, or clade, but are a paraphyletic grouping of all descendants of the last eukaryotic common ancest ...

s. In 1839, he became a member of the

Royal Society The Royal Society, formally The Royal Society of London for Improving Natural Knowledge, is a learned society and the United Kingdom's national academy of sciences. The society fulfils a number of roles: promoting science and its benefits, re ...

. John Hogg is credited with the creation of a fourth kingdom, accompanying

Carl Linnaeus Carl Linnaeus (23 May 1707 – 10 January 1778), also known after ennoblement in 1761 as Carl von Linné,#Blunt, Blunt (2004), p. 171. was a Swedish biologist and physician who formalised binomial nomenclature, the modern system of naming o ...

's Lapides, Plantae and Animalia, to classify

Life Life, also known as biota, refers to matter that has biological processes, such as Cell signaling, signaling and self-sustaining processes. It is defined descriptively by the capacity for homeostasis, Structure#Biological, organisation, met ...

, namely ''Protoctista''.

Background

In 1735, the Swedish botanist

formalized living things into two supergroups, in his monumental ''

Systema Naturae ' (originally in Latin written ' with the Orthographic ligature, ligature æ) is one of the major works of the Sweden, Swedish botanist, zoologist and physician Carl Linnaeus (1707–1778) and introduced the Linnaean taxonomy. Although the syste ...

''. All organisms were placed into the Kingdoms Plantae and Animalia. Linnaeus added a third kingdom of the natural world in 1766; ''Lapides'' ( rocks). These were deemed to be similar to plants in that they were, neither living nor sentient, i.e. not having senses. They were further characterised as solid bodied.

Fourth kingdom

In 1860, Hogg created a fourth kingdom, the ''Regnum Primigenum'' or ''Protoctista''. His rationale was simply that a kingdom of 'first beings' was necessary, as these entities were believed to have existed prior to plants and animals. Hogg attempted to justify his arguments for a fourth kingdom with '' Spongilla'', a freshwater green sponge, that was an animal known to exude oxygen in the light. However, the

photosynthesis Photosynthesis ( ) is a system of biological processes by which photosynthetic organisms, such as most plants, algae, and cyanobacteria, convert light energy, typically from sunlight, into the chemical energy necessary to fuel their metabo ...

was later shown to be a result of symbiotic '

algae Algae ( , ; : alga ) is an informal term for any organisms of a large and diverse group of photosynthesis, photosynthetic organisms that are not plants, and includes species from multiple distinct clades. Such organisms range from unicellular ...

'. Such an attempt to apply non-reductionist thought to classification systems during a period of biological debate made Hogg a protagonist within the field of nineteenth century biology along with

Ernst Haeckel Ernst Heinrich Philipp August Haeckel (; ; 16 February 1834 – 9 August 1919) was a German zoologist, natural history, naturalist, eugenics, eugenicist, Philosophy, philosopher, physician, professor, marine biology, marine biologist and artist ...

and

Charles Darwin Charles Robert Darwin ( ; 12 February 1809 – 19 April 1882) was an English Natural history#Before 1900, naturalist, geologist, and biologist, widely known for his contributions to evolutionary biology. His proposition that all speci ...

References

{{DEFAULTSORT:Hogg, John 1800 births 1869 deaths Fellows of the Royal Society British naturalists