jak. 1899] CLASSIFICATION OF BUTTERFLIES 79 



Dr. This or Mr. That, but by a study of attack -rates and death -rates at 

 different age periods in definite epidemics amongst vaccinated and unvaccinated 

 respectively (see Statistics of Sheffield Outbreak, by Barry, and of Gloucester 

 Outbreak, by Bond) ; (2) as regards the identity of variola and vaccinia, see 

 Klein's experiments recorded in Medical Officer's Report to the Local Govern- 

 ment Board for 1892-93.— Ed. Nat. Sc] 



CLASSIFICATION OF BUTTERFLIES. 



In Novitates Zoologicae, v. p. 374, ff. (1898) I published an account of the 

 structure of the antennae of butterflies as a first instalment of my " Contribu- 

 tions to the Morphology of Lepidoptera." I am carrying out these researches 

 on Lepidoptera in order to reach a basis of fact which will enable us to under- 

 stand the various structures of the exoskeleton of Lepidoptera, and will thus 

 also furnish a better basis for classification. As the number of species to be 

 examined is so very great, oversights are likely to occur ; but I hoped that, by 

 inviting criticism of my paper, such oversights would be corrected by others, 

 and thus our knowledge of the morphology and relationship of Lepidoptera be 

 advanced. Criticisms in which errors as to facts are pointed out, or in which 

 it is shown where and why my conclusions are fallacious, will have my earnest 

 consideration. 



Professor Grote, in the last issue of Natural Science, p. 440, does not give 

 any reason why, in his opinion, the characters of the antennae are "valueless 

 for taxonomy and phylogeny," and hence I have nothing to reply to this strange 

 statement. 



As regards Professor Grote's classification of Butterflies I merely say that it 

 remains for Professor Grote to show that what he styles in Papilionidae vein ix. 

 (absent from the other Butterflies, according to Grote) is not homologous of what 

 he calls in the other Butterflies vein viii. (absent from Papilionidae, according to 

 Grote). This fundamental question can be answered by a study of the develop- 

 ment of the respective veins in the chrysalis. Karl Jordan. 



Zoological Museum, Trixg, December 6, 1S9S. 



In reply to Mr. Quail's criticism (Natural Science, p. 395, December 1898) 

 of my conclusions as to the position of the Papilionides, a criticism based upon 

 his reading of the characters of Anosia, I take up these one after another. The 

 "structural blotch A" on the cubitus of Anosia may or may not be homologous 

 with the cross vein of the Papilionidae. It is a slight extension at the extreme 

 base, and is more prominent in Heliconius, where it really assumes the aspect 

 of the remnant of a cross vein between cubitus and vein vi. In both cases it is 

 situated much nearer the base of the wing than in the Papilionidae. Mr. Quail 

 is correct that I had overlooked it (I.e. p. 394). But its exact nature and mean- 

 ing are unimportant to my classification. I do not base my separation of the 

 Papilionides upon the presence of a cross vein between cubitus and vein vii., 

 but upon the existence of vein ix. in the latter group. There is no trace of 

 vein ix. in Anosia, indeed there is no room for it. Again, the homology of the 

 "structural blotch" of Anosia, of the Limnads, and Heliconians with the cross 

 vein of the Papilionides would favour my theory that this structure is a part of 

 a former general system of cross veins of the lepidopterous wing, as explained 

 in the Proc. Am. Phil. Society. A cross vein would then have run in the 

 Lepidoptera generally between v. and vii., intersecting vi., which latter vein has 

 faded out ; and thus the action by which the media has disappeared would have 

 been repeated with variations in the region below the cubitus. The cross vein 

 gradually fades out in the Papilionides themselves and is lost entirely in the 

 higher forms, so I could not have placed any reliance upon its presence in the 

 classification which I proposed. This, I think, disposes of objection " A." As 

 to " B," the " rudimentary nervure," this is equivalent to my vein viii., and does 



