( xxvii ) 



do to name all kinds of varieties in the same way. It was Staudiiiger wlio 

 first separated the varieties of Lepidoptera iuto two categories: geographical 

 and non-geographical varieties. There is indeed a great difference between 

 these two categories, as we shall see later on. Unfortunately Staudinger adopted 

 for the geographical variety the old term varietus (car.), and for the second 

 kind the term aberratio, giving both terms a definite meaning which they 

 did not originally have. He should have invented a new term at least for 

 the geographical variety. As it was, the application of rar. and ah. remained 

 in as great a muddle as before. 



While there was thus some sign that the relatiou of the varieties towards 

 each other was assuming a clearer aspect, at least to some authors, a curious 

 misunderstanding crept in, which prevented many classifiers from perceiving the 

 true relation of the varieties towards the species. It is self-evident that two or 

 more diflferent-looking animals whicli are found not to be specifically distinct 

 from one another belong to the same species, i.e. are components of this 

 species. All the components together are the species. This is a truism. How- 

 ever, systematists became accustomed to look upon that particular component 

 which was first described and named, and of which the name was accepted as 

 the name for the entire species, as being the species, while it was, as a matter 

 of course, only one of the components of the species. It is utterly wrong to 

 say that the first-described form is the species and the later-described forms 

 varieties of it. We know, for instance, that Araschnia lemma and provsa are the 

 same species ; neither levana nor prorsa is the species, but the pale spring-form 

 letana and the darker summer-form prorsa together are the sjjecies, thus : — 



levana \ 



\-= species. 

 prorsa J 



It is j)urely conventional, on grounds of nomenclatorial efficiency, and has 



nothing to do with the relation of the summer- and spring-broods towards each 



other, or with the causes and the origin of such horodimorphism, that the 



first-given name, levana, is applied to the s]ieeies. In doing this people forgot 



that the name levana, originally standing for part of the species, was now 



employed for the whole as well, and that therefore the true relation between 



the species and its components is this : — 



spring-brood levana \ 



, , = species levana. 



summer-brood prorsa J 



Or, if we use the term/, t. {= forma tempestatis) for horodimorphic forms, we 



have as formula for the insect : — 



f f. t. levamt ; 

 Araschnia levana -\ „ , 



\ i. t. prorsa. 



Instead of employing this formula, classifiers spoke and speak of a species 

 levana, meaning the spring-form, and a variety prorsa, meaning the summer- 

 form, co-ordinating the one with the other : — 



Araschnia levana ; 



Araschnia levana var. prorsa. 



