ANTHROCERA. 428 



acldlleae ab. flava, A. purpuralis ab. lutescens, A. exulans ab. flaw, A. 

 transalpine ab. lutescens, A. sarpedon &b.jtava, A. lavandulue ab. lutescens. 

 The red colour of the Anthrocerids is readily acted on by various acids 

 (vide, Brit. Noct., etc., ii., p. xi) which change it to yellow, but a careful 

 washing with water, and even long-continued exposure to the air, will, 

 in some instances, restore the colour. Fletcher says that the yellow 

 modification of colour is more or less hereditary, but only a small pro- 

 portion of offspring turn out yellow when only one parent is yellow. 

 He has never been able to obtain a pairing between a yellow male and 

 yellow female. He is inclined to believe, too, that the male is more 

 potent in carrying on the yellow colour than the female. The attempt 

 to carry on a brood of more or less transparent specimens of A.filipen- 

 didae has always failed, the offspring being normal. This tends to 

 prove that the latter is simply a pathological condition induced by 

 reduced energy in the individuals affected. 



The tendency for the red coloration to become obscurely brown is 

 of very much rarer occurrence. It appears rather frequently in A. 

 filipendulae, the form produced being known as ab. chrysantliemi, 

 A. hippocrepidis ab. niyricans, A. purpuralis ab. obscura, A. trifolii&b. 

 obscura and A. lonicerae ab. ckalybea. 



The blue-green ground colour of the wings is sometimes mixed 

 with silvery-grey or golden-yellow scales. Both forms are not at 

 all infrequent in A. exulans, and the latter is well-marked in A. 

 achilleae ab. bitorquata. Sometimes the blue-green scaling is changed 

 to a pallid brownish, as in A. filipendulae ab. yrisescemi, but this 

 appears to be a marked pathological condition, differing somewhat 

 from the preceding, and almost of the same nature as the con- 

 ditions, which produce an odd pallid wing, whilst the others are normal, 

 and so on. Then again, certain species, with normally distinct spots, 

 may present confluent aberrations, e.g., A. evidans, A. viciae, A. 

 lonicerae, A. trifolii, A. filipendulae, etc. ; others with yellow rings 

 surrounding the red spots are so modified that the pale cincture may 

 be absorbed in the red, or, on the contrary, may absorb it, extreme 

 cases occurring in A. camiolica and its allies. The abdominal red 

 belt also, in those species which possess it, may vary in colour, may 

 exist as a double or single ring, or may be altogether suppressed. The 

 width of the dark marginal band of the hind-wings also varies greatly ; 

 in some species aberrations are found in which almost the whole of 

 the red colour is absorbed. 



The variation that occurs in the mode of spotting of the Burnets 

 forms a very interesting study. The species divide up roughly into 

 the following groups : (1) With six crimson spots. (2) With five 

 crimson spots. (3) With three longitudinal blotches. (4) With five 

 crimson spots, and a sixth transverse lunular spot parallel with the 

 hind margin. The species of the latter group are strongly inclined to 

 have the crimson spots outlined with cream colour. (5) With three 

 transverse blotches, apparently formed of 1 + 2, 3 -f- 4, 5 + 6 in A. 

 cuvitri and 1 + 2, 3 -f 4, 5 + outer transverse mark of group 4 in A. 

 olivieri. On the whole, this group seems more allied to group 4 than 

 to any other. Bateson observes that a similar series of grouped forms 

 can be arranged according to the characters exhibited by the male 

 genitalia, but the two series do not correspond at all closely with each 

 other. 



