Ill 



in a far less degree than in the male. This may be a sort of weapon in the 

 battles of the males. Whether in Papilio Grayi, P. Cleotas, P. Corcdms, 

 and their allies, the serrated margin of the fore wings is limited to the male 

 sex I do not l<now, not having yet caught females of these rare species." 



Mr. Meldola exhibited the proboscis of the Sphinx referred to in the above 

 letter, and also the wings of a male specimen of Callidryas Argante, showing 

 the serrated margin. He remarked that he was indebted to Mr. Darwin for 

 having kindly placed the letter and specimens at his disposal. With 

 reference to the length of proboscis of Sphinx-moths, it was stated that in 

 the British Museum there is a South-American specimen of Macrosila 

 cluentius, the proboscis of which is 93*5 centimetres (= 9^ inches) long. 

 Both Mr. Darwin (' Fertilization of Orchids,' 1862, p. 198) and Mr. Wallace 

 (' Quarterly Journal of Science,' Oct. 1867) had predicted the existence in 

 Madagascar of a moth with a proboscis sufficiently long to reach into the 

 nectar of AncujrcEcum sesquipedale, the nectary of which orchid is from ten to 

 fourteen inches in length. This prediction, although not at present specially 

 fulfilled with regard to Madagascar, has been since shown to have a great 

 amount of probability by the discovery of a Sphinx in South America with 

 a proboscis 25 centimetres (= 9"8 inches) in length. This specimen vvas 

 also captured by Fritz Miiller (see ' Nature,' vol. viii., p. 923), and has been 

 since identified as Macrosila cluentius (see ' Nature,' vol. xvii., p. 221). The 

 selective discrimination of flowers of certain colours referred to in the fore- 

 going letter appears to afford additional proof of the fact that insects can 

 distinguish colours — a fact of the utmost importance to the theory of Sexua 

 Selection. With reference to the serrated costal margin of the fore wings of 

 butterflies, Mr. Meldola stated that this character had been shown to exist 

 in the genus Prioneris by Mr. Wallace (Trans. Ent. Soc, ser. iii., vol. iv.), 

 and in the genera Amynthia and Pyrrhosticta by Mr. A. G. Butler, but 

 that, so far as he knew, it vvas now made known in Callidryas for the 

 first time. 



Mr. A. G. Butler stated that in many of the exotic NotodontidtB he had 

 observed a fan-like tuft in the males. With reference to the Sphingidce of 

 Madagascar, he stated that he had measured the probosces of all the speci- 

 mens in the British Museum, and none of them exceeded five inches in 

 length. Mr. Butler further remarked that the whole of the Old World 

 species of butterflies separated under the Hiibnerian genus Catopsilia, the 

 whole of the New World species separated under the genus Phcebis of 

 Hiibner, all the species of the true Callidryas, Boisd., and one species only 

 of the genus Aj^hrissa, Butler, have the serrated costa in the male sex. 

 Aphrissa Godartiana, Swainson, although closely allied to A. Hartonia, 

 Butler, being similar in colour and pattern, but differing chiefly in size and 

 the shortness of the wings, has a strongly serrated costa, whilst A. Hartonia 

 has the costa smooth. With regard to the object of the serrated margin, 



