SCIENTIFIC NOMENCLATURE 19 



If, however, you had said that your dog was a setter, this would not 

 be sufficient as there are several varieties or subspecies of setters, and 

 your friend would be forced to ask, what kind of a setter? If you reply 

 that it is an English setter, then you tell him the variety or SUB- 

 SPECIES of setter you own, and his information regarding your pet 

 would be complete. (If your English setter were a duck, its scientific 

 name would consist of three terms, and might possibly be Dogus setteri 

 englishus, meaning genus-dog, species-setter, variety or subspecies-Eng- 

 lish.) This is an example of a scientific name of three terms. 



It should now be clear why it is that in certain instances a two- 

 termed (binomial) scientific name is sufficient, while in others a three- 

 termed (trinomial) name is necessary. The answer is, EXACTITUDE. 



(Lest we be charged with ignorance, and to be fair to the dog, it 

 should be admitted now that in his own family, he is a species, not a 

 genus. Thanks, Fido!) 



Let us now translate our "dog" example into a "goose" example 

 by examining the Subfamily "Geese" on the chart, and see how the 

 Geese are divided into GENERA, SPECIES, and SUBSPECIES by 

 their scientific names. There are fifteen geese of this subfamily known 

 from North America and their relationships to one another are as fol- 

 lows: 



THE FIRST TERM of the scientific name, as we know, denotes the 

 GENUS. The first eight geese, for example, are of the genus Branta; 

 there follows one of the genus Philacte, two of the genus Anser, and four 

 of the genus Chen. So that all the Geese in North America are included 

 in the four genera, Branta, Philacte, Anser and Chen, all indicated by 

 the first term of the names. 



THE SECOND TERM of the scientific name, as we know, denotes 

 the SPECIES. The first five geese, for example, are of the species B. 

 canadensis, (the second term); there follows one of the species B. ber- 

 nicla, one of the species B. nigricans, one of the species B. leucopsis, one 

 of the species P. canagica, two of the species A. albifrons, two of the spe- 

 cies C. hyperborea, one of the species C. caerulescens, and one of the spe- 

 cies C. rossi; all indicated by the second term of the names. 



THE THIRD TERM of the scientific name, as we know, denotes the 

 SUBSPECIES. When a species is composed of more than one variety, 

 each variety is called a "subspecies," and a third term is added to the 

 name to denote the name of each such subspecies. It has already been 

 noted that the first five geese belong to the species B. canadensis (the 

 second term) and it is now seen that this species, for example, is composed 

 or built up of five varieties or subspecies, viz., B.C. canadensis, B.c.occi- 

 dentalis, B.c.leucopareia, B.c.hutchinsi, and B.c.minima (the third term). 



It will now be clear to the reader that (1) a species may consist of 

 only one kind of bird, as in the case of the Wood Duck, A. sponsa, in 

 which case the single specific name sponsa is sufficient, or (2) a species 

 may be divided into or composed of more than one variety or subspecies, 



