i8 THE EVOLUTION OF 



supports it. In the remotest iuTestigable period the red 

 colour in both Papilios surely must haved turned nearly- 

 all to yellow, hence the yellow one is found there so abund- 

 antly and the red one has become so scarce. The groups 

 to which these Papilios belong, especially those of Poda- 

 lirius, in some species of which the scales are wholly dis- 

 appearing, do contain, according to my theory, butterflies 

 in a far advanced state of colour-evolution. I think it quite 

 a matter of course that, where black appears upon red, the 

 colour is at first darkened thereby, and I never intended 

 to deny that. But a single look at the family of the Pt'ent/ag 

 is enough to point out that black does just as often appear 

 upon orange and yellow without any intervention of red, 

 and that is not at all explained by the above named series 

 of succeeding colours. In ray theory, however, it can be 

 explained without the least difficulty. Finally I have to 

 point to the fact that Dr. Grafin von Linden (though it 

 is not spoken of in the account) in the report of her inves- 

 tigations about Vanessa levana L., prorsa L. particularly 

 mentions that in this species white does come on by driving 

 away black, that is: as the final colour. Exactly coinciding 

 with my views, though it is possible that this white colour 

 may be an optical colour; for optically white scales are 

 bare of pigment and accordingly lost all pigment when 

 black was driven out, which indeed with regard to the 

 final colour agrees perfectly well with my views, as can 

 be seen on page 238 and so on of my paper. 



So if I may take the liberty to judge Dr. Grafin von 

 Linden's interesting study after the revealed facts more 

 than after the written words, I find a really most valuable 

 confirmation of what my investigations have led me to 

 accept as likely to be true '). 



1) I only came to know of Dr. Grafin M. von Linden's critical study of my 

 paper on evolution of colour of Pieridae published in the »]llustrierte Zeitschrift 

 fur Entomologie, IV, p. 19 (I Oct. 1899)" after having done writing all this. I do 

 not think it of any use to refer to her paper after all the above said. Unfor- 

 tunately this learned authoress also appears not to be a genuine Lepidopterologist 



Notes from the Leyden IMuseuin , "Vol. XXII. 



