ABERRATION OF VANESSA URTIC.E, L. 8H 



just coming on, and some perfect specimens were netted. One ver>- 

 fresh Pnntia calUdire was taken just outside the Schwarzee Hotel and 

 a very small Colias palaeno in good condition, halfway up the mountain. 

 Although we passed inany likely spots, we saw only two Ihirnassiua 

 ildiidi, neither of them being within range. 



On the 21st, we came down the Nicolaithal by train, en route for 

 England, our last entomological vision being a specimen of Euvanessa 

 antiopa flying just below Tilsch, on ground which looked as if it would 

 repay a visit in search of the larvae of that species. 



An "iocolor" and "ioform" aberration of Vanessa urticae, L. 



[iritli jilate). 

 By T. REUSS. 

 In July, 1906, my attention was drawn to the important results 

 obtained from the temperature experiments of Professor Standfuss and 

 Mr. Merritield. Being interested in the biological problems 

 concerned, I then first experimented on over 100 larvae 

 of T'. urticae from two wild broods, and obtained 65 aber- 

 rations in the course of a month. These exhibited B9 of the 

 aberrative features, singled out in two columns by Mr. Raynor {antea 

 Jan. no.), whilst some also exhibited what I term "ioformity," r/c, a 

 transition of markings to V.io. My best "ioform" specimen, how- 

 ever, was bred on October 17th, as the result of an experiment 

 made by exposing the pupa to the direct and intensified sun's rays and 

 heat (48'^C.), and it so strikingly blended the characteristics of fhe two 

 species, V. io and T'. urticae, that I named it ab. infonuis (pi. vii., fig. 1). 

 This specimen was exhibited on December 2nd, 1908, at a meeting of the 

 Entom. Soc. of London. To describe and biologically explain the 

 markings of this aberration it appears desirable to consider (1) the 

 " palfeform " (fixed hereditary) details of the specimen ; (2) its 

 aberrative characters ; (3) its " io-neoform " colours and markings, 

 (progressive in the direction of V. io). 



1. PaLvEform (established hereditary) DETAILS. — The ground 

 colour of the forewings, the first costal macula, and the inner marginal 

 spot, with the adjoining yellow parts, are palseform, but browned and 

 enriched by stimulated vitality. The colours of the scales and hairs of 

 body, legs, and basal parts of wings, are also as in the parent species. 



2. Aberrative Details. — On the forewings the second and 

 third costal macuht coalesce, the two median spots absent. The 

 same partly protoform characteristics are shown in T'. urticae ab. 

 icloiusoides, Selys, and (in the costal markings) in T'. io ab. belisaria^ 

 Obth. (pi. vii., fig. 10). 



8. Io- (neo-)form (progressive) details. — L/')ier.side forcui)!;^: At 

 the apex there is a semicircle of ocelliform, metallic, white spots, the 

 lower two of which are shaded with violet by the marginal markings ; 

 the outer wing-fringes darkened ; the shape of the apex that of I', io by 

 enclosing a greater space and leaving the wings less pointed than in 

 the normal 1 . urticae. lipperside hind wine/: Colour dark velvetj'-brown- 

 red (/o-coloiir), spread over the wing-surface much as in V. io, leaving 

 the large area where the ocellus should form brown -black, with 

 lighter parts behind the three violet (/^-colour) marginal spots (de- 

 veloped in T'. in into an ocellus). These violet markings show signs 



