in 



Ueber die Farbe uud doi Polyphorphismus der Sphingiden-Raupen (Tijdschrift 

 voor Entomologie XL, 1897). 



Die Farbetievo/uiion (Phylogenie der Farben) bei den Pieriden. (Tijdschrifi. 

 der Ned. Dierk. Vereeniging, 1898). 



Mimicry, Selektion, Dativinismus. Leiden, 1903. 



Noch einmal : Mimicry, Selektion, Danvinismus. Leiden, 1907. 



Ueber die sogenannten "Schwdnze der Lepidopteren." (Deutsche Entomologische 

 Zeiischrift Iris, 1903). 



All those who wish to get acquainted with my opinions in this respect 

 and with the scientific reasons on which they are founded, I must refer to 

 these studies; two of them, which have been published separately, are rather 

 voluminous. Though the first two have been inserted in Dutch periodicals and 

 the next two have been published in Holland, they have all been written in 

 German. My preference for the English language for this work has its reason 

 in the circumstance that almost all the stricdy faunistic works about the Indo- 

 Australian Rhopalocera — Rhopalocera Malayana by Distant, The Lepidoptera 

 of Ceylon by Moore, Lepidoptera Indica by Moore, The Fauna of British India 

 including Ceylon and Burma, Butterflies by C. T. BrNGHAM, A list of the 

 Butterflies of Sumatra 7vith especial reference to the Species occuring in the north- 

 east of the Island by Lionel de Niceville and Dr. L. Martin. {Journal of 

 the Asiatic Society of Bengal, Vol. LXIV. Part II No. 3. 1895), besides many 

 other books referring to the same fauna, as those by Horsfield and Moore 

 or by Wallace and others, have also been written in English. In order to 

 facilitate the general comparative study of the Indo-Australian Rhopalocera and 

 in order to ensure in such a study as much attention as possible to my book, 

 it seems preferable to me to make use of the English language. But as in 

 that language nothing but a short communication " On the Evolution of Colour 

 in Lepidoptera" in the Proceedings oi \ki& Fourth International Congress of Zoology, 

 held at Cambridge in 1898, and an essay "The Evolution of Colour in Lepi- 

 doptera" in the Notes frotn the Leyden Museum Vol XXII, has as yet been 

 published about the said point of view, I think it is necessary for clearness' 

 sake, to shortly explain here once more my ideas on the subject. 



This, however, seems unnecessary to me with regard to the subject of 

 mimicry, and protective resemblance, about the protecting or warning colours 

 and suchlike things ; in one word with regard to the modern zoological roman- 

 ticism, which especially in the sphere of lepidopterology has indulged in 

 real orgies and has not shrunk from any excesses. For, to be sure, the fact 

 of the existence of resemblances between different species of animals, or between 

 animals and plants or lifeless objects, which resemblance often deceives the 



