INTRODUCTION. 1 1 



dient to take different dates for generic and specific names. 

 The Committee, furthermore, in one or two cases, submits some 

 decided innovations, positively at variance with the provisions 

 of any previous nomenclatural code ; believing that certain radi- 

 cal modifications are demanded by recent progress in science, 

 and that these are a step in advance. 



Referring now to the original Stricklandian Code of 1842, 

 the principal changes which your Committee proposes and 

 recommends for adoption by the Union may be summarized 

 as follows : 



(i.) The adoption of the date of the Xth edition of the l Systema 

 Naturae,' 1758, instead of that of the Xllth, 1766, as the starting-point 

 of the law of priority for names of whatever groups ; because this date, 

 1758, is in fact that of the establishment of the binomial system of 

 nomenclature in Zoology, and of its first methodical application to the 

 whole Animal Kingdom. 



(2.) The rule that prior use of a name in Botany does not make 

 that name unavailable in Zoology ; with the injunction, however, that 

 duplication of names in the Animal and Vegetable Kingdoms is to 

 be sedulously avoided in future. 



(3.) The principle of Trinomials : namely, departure from strict 

 binomiality to the extent of using three words as the name of those 

 subspecific forms which are sufficiently distinct to require recognition 

 by name, yet which are known to intergrade with one another ; the 

 name of such forms to consist of three terms, a generic, a specific, 

 and a subspecific, written consecutively and continuously, without 

 the intervention of any mark of punctuation, any arbitrary character, 

 any abbreviation, or any other sign or term whatsoever. 



Furthermore, the Committee, while insisting strenuously 

 upon the principle of an inflexible law of priority, has neverthe- 

 less sedulously attempted to guard, as far as may be possible, 

 against needless or undue rejection of names in current usage 

 in favor of obscure earlier ones which rest upon descriptions so 

 vague or imperfect that their identification can be made out 

 only by the process of exclusion, by presuming that they can 

 mean nothing else. The safeguard which the Committee pro- 

 poses for these cases is, that a name to be valid must be iden- 



