57 



fg)CIENTIFIC NOTES. 



Trimorphic Colour Variation in ckrtaixV species. — As is well 

 known, Mr. l-'rohawk has a white-belted specimen of Sesia cuHcifonnis. I 

 find other records in the Eiit. Mo. Mag., vol. iv., pp. 153 and 183, of the 

 capture of similar white-belied varieties. The question now arises — Is 

 the coloration of the belt in this species trimorphic or not ? Normally 

 the belt is red, frequently yellow (var. thynniformis), and it is now 

 well known to be occasionally white. The belt then has three 

 forms, red, yellow, and white ; but is the white brought about by a real 

 pigmentary change similar to that by which red becomes yellow? iSlr. 

 T. D. A. Cockerell writes to me : — " In flowers white is not a pigment 

 at all, but is due to air in the cells ; in most animals also white is not a 

 pigment — in fact, Jeffrey Bell, in his Comp. Anat. and Phys. (1885), 

 says (p. 271), that no distinctive white pigment is known." That there 

 is a white pigment in certain lepidoptera has been demonstrated. I 

 believe myself that there is no appreciable white pigment in Pieris ; but 

 that there is pigment in the white of Lyccena and Melanargia appears 

 almost certain, as they are so readily acted upon by ammonia, etc. 

 ^\'hether the white belt of -5". cuHcifonnis is of the same nature as these 

 or not requires proof. A case almost on all fours with the belt of 

 culiciforinis is the collar of Antia caia ; normally it is red, in some 

 varieties this and the hind wings are yellow, whilst Mr. Cockerell again 

 writes : — " I suppose you know that our American form (var. ainericana) 

 of A. caia has a white collar instead of a red one ; and according to 

 Strecker there is in Armenia and Tokat (Asia Minor) a form of A. caia, 

 in which the hind wings of the $ are pure white, those of the $ orange." 

 —J. W. TuTT. May 18M, 1890. 



Colour of the Blood in Biston hirtaria. — I should like to 

 draw the attention of entomologists to the fact that the colour of the 

 blood differs in the two sexes of Bistort hirtaria — that of the $ being 

 yellow, of the ? green. Another curious fact is the frequent occur- 

 rence of sacular distension of the blood-vessels, especially towards the 

 hind margins of all the wings. I have never met with this condition in 

 any other inject ; possibly other entomologists may have done so. The 

 condition is not perpetuated in the dried insect, owing, I presume, to 

 the complete evaporation of the watery constituent of the blood. What 

 is the cause of this imperfection, and why is it limited to Biston 

 hirtaria 'i — F. J. Buckell, Canonbury Square, N. April i^th, 1890. 



m 



URRENT NOTES. 



A new Jjritish Ichneumon, Pimp/a rufplciira, has been described by 

 Mr. G. C. Hignell, F.E.S. The species was bred from a batch of 

 cocoons obtained from Pygcera curtula. 



Mr. B. Blaydes Thompson (one of our Exchange Club members) has 

 gone to the North-West Himalayas to collect the mountain forms of 

 Indian Rhopalocera. 



