76 



but varying in regard to the marginal band to a considerable 

 extent. 



One would have expected that inasmuch as Arran and Paisley 

 are so nearly in the same latitude, that specimens from the two 

 localities in question would have been practically identical. Such, 

 however, is not the case. 



Apart from variation due to climatic conditions, i.e., Scotch, as 

 compared, for instance, with southern specimens, etc., there is also 

 another phase to be considered, i.e., recurrent variations which 

 crop up, no matter from what locality the insects are obtained, 

 such as, for instance, ab. sahiionicolur, of distinct pink coloration, 

 and various ab. discolor, i.e., darkochreous yellow. 



Apart from these, the insect runs through a whole gamut of 

 coloration, from white to deep rich tortoiseshell, represented by ab. 

 alba at one end and ab. testiidinea at the other. The latter form 

 appears to be more commonly found amongst the Scottish specimens 

 than in the south. 



I would like to refer particularly to variety ic/ninsa. While this 

 does occasionally occur from insects bred under normal conditions 

 from wild larvae, it appears to be, like ab. ichnusoides, largely the 

 result of temperature experiments. As showing what can be done 

 in the latter direction, it is on record by T. Reuss that in experi- 

 menting with some 100 larvfe from two wild broods, he obtained 65 

 aberrations, of which 39 are amongst those named by Raynor, as 

 mentioned previously, and which were largely the result of exposing 

 the pupae to the direct and intensified sun's rays. 



As showing to what a considerable extent heat will affect this 

 insect (prior to emergence), I was examining some specimens in 

 the Bond collection this week, in which there were two short series 

 of iirtiar from the same brood, one lot showing emergence before a 

 thunderstorm and the other after it. One takes it that this 

 difference in coloration, i.e., one series being considerably lighter in 

 colour than the other, would be due to the considerable difference 

 in the temperature in the period before and after the thunder- 

 storm in question. 



Chemical Action. — On September 13th, 1917, I exhibited a 

 specimen of this insect suffused with a dull plum colour. This 

 specimen was given me as having been taken wild of the particular 

 coloration in question, and at that time I had no doubt as to its 

 ho7id-jides. At a later date, however, I had an opportunity of 

 examining a very considerable collection of Vanessa nrticcr, taken 



