HISTORY OF ENTOMOLOGY. 449 



supposed essential distinction of the genus, given at the 

 head of the Class; and another, generally longer, and in- 

 cluding non-essentials^ given at the head of the Genus. 

 The first he denominated the essential, and the latter the 

 factitious or artificial character. He did not do for insects 

 what he did for Botany, draw up what he has called 

 the natural character of a genus, which included both the 

 others, and noticed every other generic distinction a . 



The older Naturalists used to treasure in their memo- 

 ries a short description of each species, by which when 

 they wished to speak or write of it they made it known. 

 Thus, in speaking of the common lady-bird they would 

 call it " the Coccinella with red coleoptra b having seven 

 black dots." This enunciation of any object was at 

 first called its Title ( Titulus\ and afterwards its Speci- 

 fic Name (Nomen specificum), and by Linne was restricted 

 to twelve words c . But as the number of species increased 

 to remember each definition was no easy task ; that he 

 might remedy this inconvenience, he invented what is 

 called the Trivial Name (Nomen triviale], which ex- 

 pressed any species by a single term added to its generic 

 appellation, as Coccinella septem-punctata ,- and thereby 

 conferred a lasting benefit on Natural History. This con- 

 venient invention has rendered it less necessary to restrict 

 the Nomen specificum to twelve words : it is desirable, 

 however, that the definition of a species should be as 

 short as possible, and contain only its distinctive charac- 

 ters. In his definitions and descriptions Linne was often 

 very happy ; but sometimes, in studying to avoid pro- 

 lixity, he forgets Horace's hint, 



a Linn. Philos. Botan. n. 87, 188, 189. 



b See above, p. 342, n. 5. c Linn. n. 291. 



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