xlvii 



I hold therefore, not only that Mr. Kivby's rule is inappropriate to the past, but 

 that it would be an uuhappy rule to adopt for llie future. 



I conceive that the practice hiiherto has beeu a t;icit recognition of the proposition 

 enunciated by Mr. Stainton — that when a genus (of which no type has been indicated) 

 comes to require division, the author who performs that operation is the person with 

 whom it lies to decide which of the dissevered parts shall retain the original name. 

 This practice has worked pretty well in the past, and will suffice for the future. 

 I apprehend that the evils which have arisen in the past have been caused by the fact 

 that the separatist, failing to recognise the original author's indications of typicality, 

 has applied the rule to cases which were not properly within its range. But assuming 

 that the separatist has not disregarded the original author's indications, or in other 

 words that the case was a proper one for the application of the above rule, then I hold 

 that his determination ought to be final and conclusive on writers subsequent to him, 

 and is entitled to the full benefit of the law of priority. 



But whilst agreeing to the above proposition, Mr. Janson goes a step further ; 

 whilst leaving the second author at liberty, he frees him from auy obligation, to 

 retain for either division the name given by the first author. And I believe 

 some naturalists go a step further still, and say ^that the second author ought 

 not to retain the original name as the name of either division, but should give 

 a new name to each division. That is to say, because we cannot call by the 

 name of Papilio all the species which Linne included under that name, therefore we 

 shall not call any of the species by that name. It is quite true that the Papilio of 

 Latreille is uot co-extensive with the Papilio of Linne; the Papilio of this century is 

 only part of Papilio of the last century ; to the characters, as given liy Linne, admitting 

 a very wide range of forms, Latreille has superadded other characters, possessed by 

 some but not by all those within the Linneau range; the effect is to restrict the 

 application of the name to a part only of the insects which Linne recognised under the 

 term Papilio; but every species of the Papilio of Latreille must be a species of the 

 Papilio of Linne, not necessarily known to Linne, but within the description given by 

 him. Florence remains an Italian city notwithstanding that Meutone has been taken 

 from Italy. Machaon may remain a Papilio notwithstanding that Priamus has beeu 

 removed. There is no misapplication of the name Papilio— only a narrowing of its 

 application. 



Consider the consequence of the rejection of the older name, instead of the 

 restriction of its limits. Genus A is divided into two; each receives a new name, 

 B and C : there is no longer a genus A. A few years later B and C are subdivided, 

 B into D and E, C into F and G : there is no longer a genus B or a genus C. A few 

 years later the same process is applied to D, E, F and G : these in turn are discarded, 

 and give place to H, I, J, K, L, M, N and O; and these again'make way for the rest 

 of the alphabet. There is an end to all stability or permanence of generic nomencla- 

 ture. At the present rate of discovery of species and publication of genera, there would 

 not be iu use twenty years hence a single generic name which is now employed. 



I care not whether it be called Papilio of Linne, or of Latreille— in fact, the genus, 

 as now understood, is not exclusively due to either, but is the result of the work of 

 both. To Linne we owe the name, to Latreille our present conception of the genus. 

 But to whomsoever the credit (such as it is) may be due, I hope that so long as genera 

 are recognised at all, so long will there be a genus Pa] ilio. 



