426 On Nomenclature. 



Ornithorhynchus being a descriptive name would conve- 

 niently apply to, and serve to suggest either species. The 

 discoverer of a plant in all respects similar to the Rafflesia, 

 except in the possession of a tall branching stem, might call 

 it Rafflesia erecta, or racemosa, but the name Rafflesia could 

 not aptly apply to or suggest both species. Two nearly allied 

 plants have, in fact, been found. 



Several naturalists have set down in their systems Didus, 

 or Dronte, or Dodo, as a genus of the order Gallinae. One 

 devises a new order, Inertes, of which he reckons it as a 

 genus. Cuvier rejects it from his arrangement as a lost fa- 

 mily of which no individual, and of course no species or 

 genus or order, is known now to exist. 



The term species is distinguished from its relative genus, 

 by suggesting a single peculiarity in which the object or ob- 

 jects called a species differ from some other species, with 

 which there is a perfect agreement in all other respects. To 

 speak of a genus with but one species is therefore an absurdity. 



The first finder of Ornithorhynchus might have given this 

 name to the single animal or brood. The name would have 

 no reference to the notion of species or of genus. But when 

 another brood was found similar in all respects excepting only 

 one permanent peculiarity or difference, then a term expres- 

 sive of the two points of difference would designate species ; 

 a term expressive of the general agreement of the two species 

 would designate genus. Order and class are merely more 

 extended genera, genus being to order in the same relation 

 as species to genus ; class is a name for a higher, kingdom a 

 name for the highest genus. 



Now, very many names have become generic, which were 

 probably once applied only to an individual or species. A 

 little shell-covered quadruped, quite new to a European eye, 

 was called by a Spaniard Armadillo. Its body was covered 

 with a dozen scaly bands. A similar animal was afterwards 

 found with fewer bands, another with one band, &c. each 

 scaly quadruped with a slight but permanent difference was 

 distinguished by a peculiar local name which now designates 

 a species. The name Armadillo thus became a title common 

 to all so covered with scales. The name has been since dis- 

 carded, and others successively substituted, as Dasypus Linn. 

 (an inconvenient name, because it had been in Greek writers 

 given already to a hare and rabbit); Cataphractus (covered 

 with armour) Brisson ; Tatusia (from a Brazilian name Tatu) 

 Cuvier. 



In a perfect arrangement the name of the genus or first 

 group beginning from species or family, should express the 



