A BRIEF HISTORY OF THE TYPE METHOD

Ronald H. Petersen

His reference to the pars typicus (1) not to the contrary, Linnaeus expressed often his belief that the definition of a "taxon" (a non-Linnaean term) must be based upon its differentium, or short diagnosis which separated it from all other taxa. Thus, in the species phrase name used by authors contemporary to Linnaeus, Linnaeus segregated by the first word of the name (the genus name), and then within the genus by the phrase following (the differentium)(2).  The nomen trivialis was simply a shorthand method by which to to refer to the species, but the nomen trivialis was not to be confused with the differentium.

Other authors made some connections between the name and the plant, although that connection rarely went beyond the citation of specimens which has been examined. To assume that such recitations were related to the present type method is quite inappropriate (1). Quite to the contrary, the European tradition linked the plant to its circumscription (see Principle IV of ICBN), that is, to its inclusive taxa (or specimens) and particularly to its differentium, which evolved into a circumscription.

Nevertheless, the need to tie the name to a plant, either living or preserved, became stronger over the years. The Lois (1867) alluded to the type method in Article 54 (" ... If a genus contains a section or some other division which, judging by its name or by its species, is the type or origin of the group, the name is reserved for that part of it."), and the reference even conforms to the present nomenclatural use of the term, rather than to other, more hopeless senses. The thought was carried to the Vienna Rules (1905) as Article 45. Partly following a call by Atkinson and Maire (3), a recommendation to Article 30 of the Brussels Rules requested botanists to establish types for all new taxa. The type

method, then, was neither foreign no alien to the European community by 1910 (4), despite its obvious disruption to the traditional association of name to differentium or circumscription.

In the 1890s a number of meetings of the Botanical Club of AAAS were held, with discussion of nomenclatural dissatisfaction at each. The Americans quickly acted outside the European Rules, and began discussions on a method by which names could be stabilized even further. At the meetings in Washington, DC, in 1903, a Commission was appointed to review varios proposals and to formulate a new set of nomenclatural rules. This they did, and at the Philadelphia meeting in 1904, the new "Code of Botanical Nomenclature" was formally adopted (unanimously) by the American botanists present. The "Philadelphia Code" enunciated for the first time the "Type Method," in the following words:

SECTION IV. APPLICATION OF NAMES

(c) In default of an original specimen, that represented by the identifiable figure or (in default of a figure) description first cited or subsequently published, serves as the type.

These "canons" together with the rest of the new Code, were presented to the Vienna Congress in 1905 by a small delegation of American botanists. The following account of that Congress, reported at the next American meeting, shows the rancor with which the Vienna discussions were viewed in the United States (Bull. Torrey Bot. Club 34: 167-168. 1907):

"The Nomenclature Commission has carefully examined the rules and recommendations adopted by the International Botanical Congress held at Vienna in June, 1905, and compared them with the canons unanimously approved by them at their meeting held in Philadelphia in March, 1904, which were duly transmitted to the Vienna Congress.

The Vienna Congress decided to base its deliberations and its code on the code of nomenclature adopted by the Botanical Congress held in Paris in 1867. At the Philadelphia meeting above referred to, this Commission concluded that better results would be obtained by abandoning the Paris code altogether and substituting for it a simpler set of rules, more satisfactorily arranged, which should recognize and emphasize the method of establishing and maintaining botanical names by the method of types. The Vienna Congress failed to recognize the principle of types, however, although its results are in advance in several ways over the Paris rules of 1867. This Commission is still of the opinion that the method of types will obtain general recognition and acceptance, inasmuch as it is the only one which promises sufficient definiteness to answer present requirements in biological nomenclature. The present discussion of this subject by zoologists is illuminating and will lead to important results. To reach greater precision we suggest certain modifications of the rules governing the selection of types enunciated at our Philadelphia meeting.

The Vienna Congress voted unanimously that the principles of nomenclature should not be arbitrary, but subsequently adopted, though not unanimously, a list of several hundred generic names of plants to be excluded from the operation of all nomenclatural rules. We regard this action as in the highest degree arbitrary, as controverting a cardinal principle; and no method is provided for fixing the types of the genera which it proposed to maintain or reject.

The treatment of homonyms was not given the importance at Vienna that this Commission believes necessary, although we are now of the opinion that the canons of the Philadelphia coe relating to homonyms were framed in a somewhat more exclusive nammer than is desirable, and we recommend some amendments to those canons.

It was unanimously agreed at Vienna to maintain the oldest specific name when a species is transferred from one genus to another, or the oldest subspecific or varietal name when a subspecies or variety is transferred from one species to another; but, when the rank is changed from species to subspecies or variety, or vice versa, the name need not be maintained, although it is desirable that it should be. To meet this agreement the Philadelphia code requires modifications, as shown by the amendments herewith recommended.

By a close vote, the Vienna Congress called for all descriptions of new species or genera, published after January 1, 1908, to be accompanied by a diagnosis in the Latin language. This requirement reaches the height of arbitrary action, and we do not regard the subject as one over which any botanical congress has jurisdiction. The progressive disuse of Latin, its elimination from the curricula of scientific schools, and the general teaching of two or more modern languages, lead us to regard this action as unnecessary and unwise."

And so the lines were drawn. The Americans, now fully committed to their Code (thereafter known as the "American Code"), including specific references to the type method, and Europeans, still attempting to revise the original "Lois" to deal with ever more complicated situations, remained at loggerheads for years. The principle which slowly eroded the European position was that of nomenclatural stability.

The Americans has been vehement on three subjects: 1) the type method and its application to all names and all ranks, including retroactive typification; 2) objection to the arbitrary establishment of starting dates (the Brussels Congress of 1910 had established the principle of later stating points for various plant groups, much to the distaste of the Americans); and 3) the leniency with which the European rules dealt with homonyms. Although European codes had discouraged the use of identical names for the same rank of taxon, practice was lenient, and several glaring instances had arisen to the contrary. In short, not only were various taxa known by the same name, but in the absence of some definitive neams of securing each name, the taxonomic sense of names was often found to "float" from one taxon to another.

The first European workers to succumb to the type method concept were the British, perhaps because of common language and better communication with the Americans. The subject was discussed at some length at an Imperial Botanical Conference (London, 1926) and the report from that conference included the recommendation that the type method be adopted in future revisions of nomenclatural rules. The final blow came when the subsequent International Botanical Congress was convened in Cambridge (1930), with English-speaking botanists again greatly out-numbering all others. Without prolonged debate, the type method was adopted as Article 18 and Recommendations IV-VII as follows:

1) Numerous cases of this kind might be cited among the Fungi. Following the above recommendations would largely obviate the need of a lengthy list of nomina conservanda.

Of course, inevitably problems arose with the simplistic approach toward typification taken at Cambridge. In almost no instances had an author explicitly stated a type specimen as part of this description, except in some American publications conforming to the American Codes. Could type specimens be selected for those names published previously ("retroactive typification"), or should typification begin only with the comtemporary names published under the Cambridge Rules and later? These questions, assuming as they did the acceptance of the type method, went even more strongly against the grain of the "anti-type" workers than the type method itself. Discretion dictated that retroactive typification be introduced as gently as possible, so Art. 18 (Cambridge) was written in present tense only, with no reference to retroactivity. Recommendation V, however, spoke to later revision of genera or other groups, and while Rec. VI did not specifically speak to retroactive typification, the examples following it assumed retroactivity. Of course, as recommendations, these items were not .pa "binding" on taxonomists. In the years during which the controversy arose, debate continued, but the Amsterdam Rules (adopted in 1935) did not reflect it.

After the years of World War II, at the Utrecht Conference held prior to the Stockholm Congress (1950), Dr. Lanjouw, the Rapporteur-General, proposed certain revisions to Art. 18 (Amsterdam), including several terms to denote categories of type specimens selected in the absence of a "nomenclatural type". These were adopted, together with the term "holotype" at the Stockholm Congress, and into the Stockholm Code, as part of Art. 18.

Such delineations separated type specimens into those which were selected and broadcast gy the original author from those selected by later authors. A proposal by Fuchs (Taxon 7: 219) called for the insertion of additional terminology which would hopefully draw even finer lines and clarify the terms already in existence.

In Fuchs' proposal, the absence of the terms isotype and paratype indicated that these were to be dropped, assumedly in favor of merotype and interpretotype respectively. Eentually, the entire proposal was rejected, but the Rapporteur-General made the point that all these new terms could be used when appropriate situations arose. Other terms not adopted, have been added to the lexicon (see Appendix 00; glossary of type terminology)

At the Stockholm Congress, problems of type selection had become clear, and Appendix I was added to the ICBN, growing subsequently into the "Guide for the determination of types." This section persisted for many years as a guide of recommendations, but finally (Berlin, 1986) was absorbed into the text of the ICBN itself as recommendations within the section on typification.

References:

 (1) cfr. Croizat. Taxon 2: 105-107. 1953.

(2) Stafleu, Linnaeus and the Linnaeans; Svenson, Taxon 2: 55-58.

(3) Actes Congress Brusseles, vol. 2: 65-68.

(4) Suringer, p. 12; Croizat. Taxon 2: 105-107.