SCIEXCE- G OS SIP. 



light will form white. This we see from fig. 7 is cyan 

 blue, a light greenish shade of blue. The green- 

 filter negative we print, not in green, but minus 

 green, a pink or light magenta colour ; and the blue- 

 filter negative we print, not in blue, but in minus 

 blue or yellow. Each of these three colours, there- 

 fore, reflects two and absorbs two of the three 

 primary colours used by Clerk-Maxwell to form 

 white light. 



Fi^r. 8 shows us the result of printing overlapping 

 discs in these minus colours. The yellow printed 

 over cyan blue forms green, the yellow printed 

 over the pink forms red. the pink printed over cyan 

 blue forms pure blue, and where all three overlap 

 in the centre of the diagram all three colours are 

 absorbed, and we get no light reflected to the eye — 

 "black. E. F. and G. fig. 9. represent prints from 

 the test -object negatives printed in the minus 

 colours, and H represents the remainder of the 



white light reflected from the white paper after 

 undergoing absorption by the pigments superposed 

 upon it. and is a correct colour copy of the test 

 object A. 



We must remember that the diagram fig. 9 

 represents what happens when we photograph 

 colours in great purity. In photographing from 

 Nature the negatives are not nearly so widely 

 different one from another as they are represented 

 here; because in Nature objects always reflect a 

 certain amount of white light, and therefore are 

 represented by some amount of deposit in all three- 

 negative;. Fiis. 10, 11. and 12 are prints from an 

 actual negative of a brightly coloured poster (see 

 p. 108). A is the print from the red-filter negative. 

 B from the green-filter negative, and C from the 

 blue-filter negative. 



(To oe continued.') 



BUTTERFLIES OF THE PALAEAECTIC KEG-IOX 



By Hexey Charles Law©, M.D., M.RX.S., L.E.C.P. Lovd.. E E - 



l Continued from page 73*.) 



(PIER IS continued.) 



23. P. ehioridiea. Hab. 712. 5. Lg. B. E. 

 34. PL YII. fig. 2. 



27 — ±1 mm. 



Wings white. F.w. with on. marg. slightly con- 

 cave. The marg. band consists of blackish dashes 

 to the number of about five, running from the 

 margin inwards : internal to these there is in 1 a 

 black band running downwards from the costa. 

 The discal spot is white in the centre. g with 

 the usual black spot near the in. marg., but it is 

 somewhat faintly marked. H.w. white and un- 

 spotted in $ , but with smaU marg. black spots 

 in 1 . Ujs. f.w. arranged as in P. daplidice. but 

 the green colour of the on. marg. is of a much 

 more delicate tint. H.w. of the same tint of light 

 bluish-green, with white spots arranged as in 

 P. daplidice., but longer and narrower : specially 

 the marginal spots. 



Hab. SJE. Russia, -rarepta. Province of Oren- 

 bourg ; Ural : Turkey : W. Asia : Amasia and Tokat 

 (Asia Minor) ; Steppes of Kadomya ; Persia : 

 Pamir ; Transalai ; Amdo : Altai, Barabinsky Steppe, 

 Kurai, Tchuja Steppe (Elwes). V.. YL Second 

 brood Tile, at 6000 ft.. Bashkaus down to 

 2,000 ft. i£ These differ only in their size from 

 those of the first generation." (Elwes. T.E.S . Sept. 

 > 



24. P. iranica Biemert Diss. p. 26. Stgr. Cat. 

 122. 



36 mm. 



(1) This series of articles on Butterflies :: zh-e Palaearctic 

 Region commenced in Sciz: z- 3 --:?, So. 61, .Tone 1889. 



Somewhat like P. daplidice, but smaller. Apices 

 of f.w. with black rays, enclosing rounded white 

 spots. Ew. with black streaks and snbmarginal 

 spots. Neuration of n.s. marked with yellow. 



Hab. Pamir — Persia. Y., YI. A rare species. 

 occurring at high elevations. 



Genus 11. A3TH0CHABI8 Boisd. 



Moderate-sized or smaU butterflies, having the 

 antennae short and with a distinct club. Palpi 

 projecting beyond head and hairy. Subcostal 

 nervure with five branches. Wings more or less 

 rounded as in Pieris. of a white or yellow colour. 

 Fore wings with a black apical patch, and with a 

 black discoidal spot. Hind wings chequered or 

 striped beneath with green, yellow or orange, and 

 sometimes with silvery patches. Larvae green, 

 narrowed at the extremities. Pupae boat-shaped,, 

 with wing-cases proportionately large. 



This genus is represented :r_ England bj the 

 common "orange-tip" butterfly, which has the 

 wings tipped with bright orange-yellow in the 

 S ; whereas the S? is merely white and black 

 above. 



The genus may well be divided into two groups 

 (in respect of the Palaearctic species) thus : — 



I. Fore wings without orange tips in either sex, 

 ground colour white or yellow. Only the first 

 branch of the subcostal nervure thrown off before 

 the end of the celL This is the genus PhylloAarxs 

 of Schatz. 

 " A. h. wings striped beneath. 



1. A oelemia. 



2. „ falUm. 



