A part icular species receives a composite name. embracing first that of the genus, and, second. that of the species; thus, the common cat is Fclis domestica.
Scientific Nomenclat urc.—The custom, above stated, of giving to each animal a double name, that of its genus and its species. arose with Linn:ens. and is called 'binomial nomenclature: It answers to a man's family and individual or 'Christian' name, as Smith, John. It always consists of Creek or Latin words, or of words put into Latinized form. partly because of a traditional custom descended from the early au thors, who wrote only in Latin, but mainly be cause it is thus made comprehensible to readers in all languages. Furthermore, great confusion would follow the attempted use of vernacular names alone. since many different animals are given the same name in popular speech, while the same animal is known by various names in different localities. 'Robin' means several very diverse birds to persons living in America, Great Britain. India. or Australia, but Turdas migratorius is unmistakably the American thrush, locally called the robin. Theoretically, these names are supposed to be suitably applied. Thus. tunlus is the old Latin term for a thrush like bird, and migratorius. the Latin adjective `migratory.' It often happens. however, through the misapprehension or ignorance of the person who first applies the name, that unsuitable or positively erroneous appellations have been given, or wrong eollocatinns have been made. A subsequent student. discovering this error, or taking a different view of the animal's relation endeavors to correct it by giving it a new, and. in his opinion. better name; or he may transfer it to another genus hut retain the specific name. A third writer, not knowing that the same animal has been previously de scribed and named, may name it something en tirely different. These changes and duplications vient on almost unchecked until the middle of the nineteenth century, when the British Asso ciation for the Advancement of Science and ether influential bodies of naturalists devised means of regulating the matter. which resulted in certain now generally aecepted rules. the sub stance of which is as follows: A name for a new species is not recognized in science, unless it is in the customary binomial form (the two parts agreeing in number and gender), and has been accompanied by a description hp which the ani mal may be satisfactorily identified. and which
is published in some book or periodical accessible to students in general: and when this has been done. no other person may give the animal a different specific name. This is called the rule of priority—that is. the first name legally ap plied must remain las a mere label I. whether it is subsequently found to have been well chosen. or not. A limit. however. was found necessary to this rule, and it is therefore agreed that no name previous to the one made or sanctioned by Linmens in the tenth edition of his •y.strma Saturn shall lie reeognized. Certain minor limitations arc also made for local needs —as. for example. with reference to Balinesque in the United States. In zoological or botanical nomenclature, a generic name can be applied only to one group of organisms. If it is subse quently given to something else the new applica tion will not bold. According to one code. at least. a generic name that has disappeared by fusion of genera or the splitting of a genus nit wit be used again. In scientific works, the tech nieal name of an animal is often followed by the name (usually abbreviated) of the man who named it as a whole, as Turdus mipratorius. Linn.; but if the generic name was made by one man and the specific by another, both authorities may be given, in order to avoid any mistake, thus: Bluebird. Sialia sialis (Linn.). Halde mann. Latterly. the recognition of subdivisions within species, called subspecies, races. or varie ties, has led to the addition of a third name in many cases, especially among birds—for ex ample, Falco percyrinus anat um means the (American) variety anatum of the European peregrine falcon, or our duck-hawk. Another custom is that all specific and varietal names shall begin with a small letter, even when 'prop er' adjectives or nouns. Similar rules and ex planations apply to the names of the higher groups, which are capitalized, always in the plural, and, iu the case of the family, take the termination ida', which in zoology invariably in dicates a group of family rank. (Note.—In the present work the rule of technical books is not followed as to the initial of specific names, which are capitalized as they would be in English.)