GRAPTA V. 



or coloration. Nearly all these are generic, that is, they belong to all the mem- 

 bers of a group, and the last two only, markings and coloration, are relied on for 

 separating species. These are always variable, and to distinguish between essential 

 and non-essential variations is often very much a matter of individual judgment 

 where one may be right or wrong and where opinions will differ. ]\lany species 

 are distinct beyond all doubt, but very often one form runs into another, or seems 

 to branch from another, or several seem to be intermediate between two that are 

 themselves distinct. To determine therefore which of these is a good species, and 

 which is a variety, is difficult and almost always unsatisfictory. So in this un- 

 certainty some naturalists name as distinct every form that presents differences 

 tliat are tangible enough to be described intelligibly, while others rest upon the 

 broad and comfortable ground that closely allied, or even tolerably distinct, forms 

 in which there ean be shown intergrades, are to be classed as a species and its 

 varieties. Notwithstanding, it is certain that, among the butterflies, the prejiai-a- 

 tory stages of such allied forms are often found to be abundantly distinct, as in the 

 case of the Graptas C album, Satyrus and Comma, all of which, judging by the 

 imago alone, might be considered as one species, and indeed have been by expert 

 lepidopterists. Yet, the larvie of all of them being known, they are shown to be 

 not merely distinct species but separated by a much wider interval than are many 

 others. On the other hand, and exactly the reverse of this, images undeniably 

 distinct may prove to be but one and the same sjjecies, as in the case of the two 

 varieties of Inicrro'/ationis and the three of Ajax. 



No doubt very many of the present names of species of butterflies are to be re- 

 garded as provisional, always subject to rectification. But before the first step can be 

 taken towards correct knowledge, differing forms of imago must be distinguished 

 by name so as to be recognised and their study faciliated, instead of being thrown 

 together indiscriminately, and lost sight of as varieties of this or that species, when 

 in most ca.ses absolutely nothing is known al)out them, and any opinion is, at best, 

 but guess-work. But when such forms are found by breeding from the egg to be 

 only varieties, they will take their proper places in the Catalogues and yet lose no- 

 thing of interest, and will help to form the material by which the naturalists of the 

 happy future will read clearly the riddles that as yet perplex us. 



