THOMPSON, JOHN VAUGHAN

(b. Berwickupon-Tweed, England, [?], 19 November 1779; d. Sydney, New South Wales, Australia, 21 January 1847)

natural history.

Little is known of Thompson’s early life beyond the fact that he spent part of it in the vicinity of Berwick-upon-Tweed, in northern England, where he studied medicine and surgery. In March 1799 he was appointed assistant surgeon to the Prince of Wales Own Fencible Regiment, which had been raised by Sir William Johnston in 1798. Thompson was promoted, after his transfer as assistant surgeon in the 37th Regiment of Foot, on 3 July 1800, to surgeon in June 1803, staff surgeon in December 1812, and then to deputy inspector general of army hospitals in July 1830. In 1835 he was posted as medical officer to the convict settlements in New South Wales, a post he held until February 1844, when he retired on half-pay.

Thompson’s early service with the medical department of the British army coincided with the Napoleonic Wars. In December 1799 he went with his regiment to Gibraltar. Early in 1800 he was posted to Guiana and the West Indies, at that time a theater in the war between England, and France and the Netherlands. Thompson’s stay gave him the opportunity to familiarize himself with the local fauna and flora. He is said to have returned to England in 1809 (although one of his letters in the archives of the Linnean Society is headed London April 7, 1807, thus suggesting that his service in the West Indies was interrupted by a trip to England).

Three years later Thompson was sent to the Mascarene Islands, where it is claimed one of his duties was to introduce the use of vaccine into Madagascar, although in official correspondence of this period he is styled “Government Agent for Madagascar,” which suggests that he was also charged with diplomatic duties. From 1816 to 1835 he was stationed at Cork (often referred to as Cove of Cork) in Ireland, where he undertook much of his research on marine invertebrates. Indeed, this period proved to be the most fruitful of his life. His later post in New South Wales was not distinguished by work in natural history, although he returned to an earlier interest in the introduction of useful plants to the colony.

Thompson’s personal life remains largely an enigma. It is not recorded whether he married, and no personal accounts from friends or acquaintances appear to exist. This was perhaps the result of his official duties, which kept him in relatively remote stations, away from the main centers of intellectual and scientific development in the British Isles. He was elected a fellow of the Linnean Society of London on 6 February 1810, and he corresponded–and evidently was on familiar terms–with Alexander MacLeay, a former secretary of the society, who was later appointed colonial secretary to the government of New South Wales. Thompson’s work on marine invertebrates was to lead him to a number of revolutionary new concepts in fundamental systematics, which brought him into acrimonious conflict with the zoological establishment in London. His correspondence and published writings of that time suggest a man impatient with the conservatism of his opponents, and eventually embittered by their opposition.

Thompson’s biological publications fall into three categories: his earliest writings on botany, a subject to which he returned in later life; his writings of a general nature on zoology; and his absorbing and most valuable contributions in marine zoology. He made little contribution to medical science, although he published in 1832 a pamphlet entitled The Pestilential Cholera Unmasked . . ., a work devoted to diagnosis and treatment of cholera, but exhibiting little understanding of the causative factors involved in the disease. The pamphlet was topical, however, because cholera had been spreading westward from Asia during the previous decade, and the year 1832 saw the first major outbreak in the British Isles.

Thompson’s early preoccupation with botany is shown by the publication in 1807 of A Catalogue of Plants Growing in the Vicinity of Berwick-upon-Tweed, a competent local flora. That same year two of his botanical communications were read to the Linnean Society in London. The first, “On the Genus Kaempferia,” was primarily concerned with the systematic arrangement of the genus. The second, “An Account of Some New Species of Piper [pepper], With a Few Cursory Observations on the Genus,” was published in 1808. This paper is interesting in that it gives incidentally a list of his travels in the West Indies, and his observations on the genus being made in Trinidad, Saint Vincent, and Grenada. His stay in Trinidad also resulted in an unpublished paper entitled “Description of a New Genus of the Natural Order of Myrti,” which was read on 3 March 1812 to the Linnean Society.

During Thompson’s stay in Mauritius, he continued his botanical studies and compiled Catalogue of the Exotic Plants Cultivated in the Mauritius . . ., which was published anonymously, but according to Thompson’s claim after the suppression of the title page bearing his name (presumably someone wanted to deprive Thompson of the credit), in November 1816, soon after he left the island. The catalogue was the first work on the plants of the island to be published locally, and is useful in listing the dates of introduction of many of the exotic forms grown in the Botanic Gardens and elsewhere. It also shows Thompson’s interest in the importation of useful plants, an interest he shared with many other colonists of the time. Thompson’s last botanical studies, which he wrote after he had settled in New South Wales, dealt with the importation and cultivation of cotton and sugarcane.

Thompson’s miscellaneous zoological publications began with his “Description of a New Species of the Genus Mus, Belonging to the Section of Pouched Rats,” written in Jamaica; the paper was read in 1812 and published in 1815. In 1829 he published an account of his study of bones of the extinct Mascarene bird fauna made during his stay on the islands; the paper is entitled “Contributions Towards the Natural History of the Dodo . . . a Bird Which Appears to Have Become Extinct Towards the End of the Seventeenth or Beginning of the Eighteenth Century.”

It was apparently while returning from Mauritius in 1816 that Thompson made his first study of marine invertebrates. South of Madagascar he observed a puzzling luminosity in the sea. He trailed a muslin hoop net over the stern of the ship and caught a profusion of small marine animals hitherto invisible in the water. Thompson has been credited with being the first person to use a plankton net, and there is little doubt that his use of it in July or August 1816 was his own idea entirely; but he was anticipated by John Cranch, who used a similar tow net on James Kingston Tuckey’s expedition to the River Zaire (or Congo) in April 1816. Thompson, unlike Cranch, lived to use his muslin net to catch marine plankton for many years.

In 1827 Thompson published Memoir on the Pentacrinus europaeus, in which he announced the discovery of a shallow-water European species of crinoid echinoderm in Cove harbor. The crinoids, especially the feather stars and sea lilies, were known only from dried specimens found in the West Indies, and their affinities were little known. His note added considerably to what was already known from the work of J. S. Miller. Thompson returned to the subject of Pentacrinus in 1836, when he showed that it was the young stage of the European Comatula; at the same time he described the then almost unknown polychaete Myzostomum costatum, commensal on the feather star, although he referred to it as a “complete zoological puzzle!”

One of Thompson’s principal contributions to zoology was the discovery that certain planktonic forms of crustacean, then known by the genus name Zoea, undergo metamorphoses until recognizable as the young of the European edible crab (Cancer pagurus). He published his findings as the first of his memoirs in the Zoological Researches . . ., but he failed to prove the complete metamorphic cycle because his zoea died in the process of change; it was only by comparing them with ova from a berried female crab that he was able to deduce the relationship. Thompson’s announcement was accompanied by a second memoir “On the genus Mysis,” however, in which he showed that the mysidacean crustaceans hatch in a form very similar to that of the adult. Both memoirs appeared only months before Rathke’s work on the development of the crayfish (Potamobius, formerly Astacus), which demonstrated that the young hatch at a late stage of development. It is not surprising then that many established zoologists treated Thompson’s claim of metamorphosis in the Crustacea with distinct and often derisory doubt. The issue was a serious one, for the taxonomy in use at the time, as expounded by William Leach and Georges Cuvier, distinguished the Crustacea from the Insecta on the grounds that the development of the former proceeded directly and without metamorphosis. Nevertheless, Thompson was soon able to prove his hypothesis. In his third memoir in the Zoological Researches . . . (1829), he described a successful experiment of 1827 in which he kept an ovigerous crab in captivity and examined the newly hatched larvae. In 1830 he claimed to have observed newly hatched larvae of eight genera of brachyuran Crustacea to be zoea; in 1835 he published notes on the natural history of the pea crab Pinnotheres (a commensal of the mussel, Mytilus), in which he again observed the larvae hatched as zoea; and in 1836 he published a report on his experimental hatching of the eggs of the spider crab Macropodia rostrata, as well as other papers on the development of Crustacea. Certain zoologists, notably John O. Westwood, refused to be convinced of the truth of Thompson’s observations, even denying altogether the evidence that he presented, and the controversy became heated. Eventually others took up the problem and confirmed Thompson’s findings.

Thompson’s second important achievement in marine biology was his discovery that cirripeds are Crustacea; in the system proposed by Cuvier, they had been designated as a class of the Mollusca. By using his plankton net, Thompson captured some small translucent crustacean larvae, which he kept alive in captivity. He discovered that these animals metamorphosed and settled as acorn barnacles. His brilliant yet simple demonstration of the systematic position of the cirripeds was published in a fourth memoir in the Zoological Researches . . . (1830). Thompson’s contribution to the biology of the cirripeds did not end with this study, for in 1836 he contributed a paper on the barnacle Sacculina, a parasite of the shore crab Carcinus maenas, in which he revealed its true nature and identified and described its larval forms.

Thompson’s third major achievement in marine biology was the recognition of the class of animals he named Polyzoa. These animals had been formerly included as part of a heterogeneous collection of enigmatic invertebrates, the so-called zoophytes; but he showed that they were distinct from the colonial hydroids and the ascidians, with which they had been sometimes confused. The term Polyzoa received considerable usage, especially in Great Britain, but it was eventually dropped in favor of Bryozoa, which had been proposed almost contemporaneously.

John Vaughan Thompson was a practical naturalist; his use of the tow net and his observations of the living animals enabled him to make a very real contribution to marine zoology. Moreover, he showed an alert appreciation of the implications of his observations that were quite remarkable in a man untrained in the natural sciences and isolated from the mainstream of zoology. He was largely denied during his lifetime the acknowledgment that he deserved; and it has indeed only been during the second half of the twentieth century that his considerable contributions have been adequately recognized.

BIBLIOGRAPHY

I. Original Works. The most important of Thompson’s works on marine invertebrates are the Zoological Researches and Illustrations (Cork Ireland, 1828-1834), a set of five scarce pamphlets, recently reprinted by the Society for the Bibliography of Natural History (London, 1968); and The Memoir on the Pentacrinus europaeus: A Recent Species Discovered in the Cove of Cork (Cork, 1827).

The following papers appeared in serial publications; (letter to the editor) concerning the metamorphosis in brachyuran crustacea Zoological Journal, 5 (1831), 383-384; “Memoir on the Metamorphosis and Natural History of the Pinnotheres, or Pea-Crabs”, in Entomological Magazine, 3 (1835), 85-90; “Of the Double Metamorphosis in Macropodia Phalangium, or Spider-Crab ...”, ibid., 3 (1836), 370-375; “Natural History and Metamorphosis of an Anomalous Crustaceous Parasite of Carcinus Maenas, the Sacculina carcini”, ibid., 452-456; “Memoir on the Star-Fish of the Genus Comatula”, in Edinburgh New Philosophical Journal, 20 (1836), 295-300; and “Memoir on the Metamorphosis in the Macrourae or Long-tailed Crustacea, Exemplified by the Prawn (Palaemon serratus)”, ibid., 21 (1836), 221-223, The botanical works include Catalogue of Plants Growing in the Vicinity of Berwick-upon-Tweed (London, 1807); and Catalogue of the Exotic Plants Cultivated in the Mauritius. . . . (Mauritius, 1816).

II. Secondary Literature. See the introduction by Alwyne Wheeler to the facsimile of Zoological Researches . . ., published by the Society for the Bibliography of Natural History (London, 1968), i-vi, for an appreciation of Thompson’s work. See T. R. Stebbing, et al., “The Terms Polyzoa and Bryozoa”, in Proceedings of the Linnean Society of London, session 123 (1910-1911). 61-72 for notes on the proposal of the term Polyzoa; and R. E. Vaughan, “A Forgotten Work by John Vaughan Thompson”, in Proceedings of the Royal Society of Arts and Sciences of Mauritius, 1 (1953), 241-248,for an account of the catalogue of exotic plants in Mauritius.

Alwyne Wheeler