COLOUR IN LEPIDOPTERA. 21 



is always replacing another. For the ontogenetical investi- 

 gation, however, mostly tropical species are wanted; merely 

 the difference between both sexes oi Antocharis cardaminis L. 

 can also be studied in Europe. The cf of this butterfly can 

 perhaps lead to a very important investigation. It may be 

 admitted as it seems from the investigation of Fieris bras- 

 sicae L. by Dr. Urech and Dr. v. Bemmelen that in the 

 oldest investigable state of this butterfly there is absolutely 

 no red pigment to be found, but only yellow (green). Now 

 this species, to my theory is very much advanced in colour- 

 evolution, even much farther than Papilio Podalirius h. in 

 which indeed, some red (though very little) has yet been 

 found. A. cardaminis L. also is very advanced, however 

 not so far as the above named Fieris^ as the (ƒ shows 

 still a little orange-tinted red on the wings. If this view 

 be right some red also must still be existing in the oldest 

 investigable state of A. cardaminis L., that is in the wing, 

 before the pigment has penetrated into the scales; though 

 probably very little, and also faded into orange. Now as 

 the remaining quantity of red can only be so very small, 

 may be it is impossible to trace it in this case, but yet 

 it seems desirable that one should try to do so, for if it 

 were found, however little it might be, it would give strong 

 evidence to the justness of my view. Such an investigation, 

 however, ought to be done most accurately and closely 

 directed to the point. Of course 1 allude to the pupae 

 of (ƒ(ƒ, with the 9Q ^^he chance of finding still some red 

 or orange is certainly very small. If indeed those colours 

 could still be found in the Q pupae, the question might be 

 considered as very near to its solution. But from the tropical 

 countries where such remarkable polymorphical forms are 

 found, as well as such very large Lepidoptera, true know- 

 ledge in this matter will have to come forth. Only there, 

 too, the forms of Papilionidae and Pieridae whose wings have 

 already more or less lost their scales, can be investigated. 

 In Europe only the ontogenetical study of the almost scale- 

 bare spots in 99 ^^ Aporia crataegi L. still can be of 



Notes from the Leyden Museum, Vol. XXII. 



