114 BIOLOGICAL LECTURES. 



distinguish members of a conventional series. Mesencephalon, 

 prosencephalon, and metencephalon designate members of a 

 natural series, and the prepositions have the force of adjec- 

 tives; see pp. 144-150. 



Base (verbum basale). The original or more essential ele- 

 ment of a derivative, as distinguished from prefixes, suffixes, 

 inflective terminations, etc. 



Derivative. A word derived or formed either immediately 

 or remotely from another; e.g., inorganic, organize, and organs 

 are derivatives of organ. 



Correlative Names. These are derivatives containing no 

 obvious locative element, but intended to indicate some relation 

 between the part so designated and the part designated by the 

 base; e.g., fissura calcarina indicates the collocation of an ectal 

 fissure with the calcar, an ental ridge. 



Eponyms. Personal names, that is, derived from the names 

 of individuals; e.g., fissiira Sylvii, pons Varolii. These were 

 discarded by me in 1880, and as they are condemned by the 

 German committee most of them will probably disappear. An 

 exception, perhaps, should be fissura Sylvii (p. ooo). 



Pecilonymy)- Proposed by me in 1889 as a niononym for 

 terminologic variety or inconsistency within a single article or 

 work; e.g., the use of fissura and sulcus for the same cerebral 

 furrow ; of centralis and Rolando for the same fissure. Between 

 pages 464 and 507 of Schwalbe's " Neurologic" occur Crus 

 fornicis (498), Fornix-schenkel (464), Fornix-satilchen (507), 

 Gewolbe-schenkel (464). His ('95) adopts Foramen interventri- 

 culare, but uses Foramen Monroi on page 166, and " Monro schen 

 Locke" on page 167. 



Direct Pecilonymy. In the cases mentioned above, and 

 others that might be adduced from nearly every work known 

 to me, one and the same part is designated by two or more 

 substantives, or words used substantively. This is direct 

 pecilonymy. A special variety of it occurs when different 

 generic names are applied to two homologous parts; e.g., in 



1 From TTOIK^XOS, various, changeful, inconstant ; compare 7roi/a\6/3oi;Xos, of 

 changeful counsel ; pecilopoda, various footed. The unfamiliar term is perhaps 

 the less objectionable in that it stands for a habit which may ere long be eradicated. 



