LINNBAN SOCIETY OF LONDON. 29 



black apex of the fore wing wliich are characteristic of their 

 locality, most of theiu too the very pale buff ground-colour which 

 is comiuou there. The London bred specimens from Fife parents 

 afford an interesting comparison, having the markings almost 

 equally well developed, but greyer, and the ground-colour 

 commonly craam rather than pale buff. 



In comparing the bred with the captured specimens, the former 

 are of course fresher and the dark markings therefore clearer and 

 sharper. Apart from this there is, Mr. Turner considers, a 

 tendency tovvards an intensification of the dark markings, 

 especially of the summer brood. Mr. AV. G. Sheldon on the 

 other hand considers that the female offspring of Lapland hryonice 

 exhibit, when bred in Eugland, a reduction of their characteristic 

 features. But allowing all weight for slight effects, probably due 

 to something unnatural in the conditions, it is quite evident that 

 Mr. Main's conclusion is sound and entirely borne out by the 

 extensive material kindly lent by him. Many local races of 

 P. rapre are distinguishable : these differences are hereditary 

 and not acquired. These small variations, many of them ex- 

 ceedingly small, are transmitted by heredity. 



b. Local British Races of the Moth Aplecta nebulosa bred in the 

 London District. — This Noctuid moth is well known to occur in 

 Delamere Forest, Cheshire, in three forms — (1) dark grey forms 

 which are much the commonest ; (2) a small percentage very 

 much darker with grey fi'inges (var. robsoni) ; (3) a much smaller 

 percentage quite black with white fringes (var. thompsoni). In 

 breeding (1) behaves as a Mendelian dominant, (2) a hetero- 

 zygote, (3) a recessive. When bred from the egg in the London 

 district by Mr. Main and Mr. Harrison, not only did the appear- 

 ance of all three forms remain unchanged, as everyone would 

 expect, but the same was true of a pale local race found in 

 Argyllshire. Examples of these and of the Cheshire forms have 

 been kindly lent by Mr. Main for exhibition. 



c. Hereditary Transmission of Small Variations in W. African 

 Butterjiies of the Genus Hypolimnas. — I here include two examples 

 in the same genus Hypolimnas, both due to the careful and 

 accurate work of Mr. W. A. Lamborn in the Lagos district of 

 AVest Africa. The first is of great importance, because it not 

 only adds to the evidence here summarised but also helps us to 

 understand how two very different mimetic patterns ai'ose. The 

 West African Hypolimnas dubia is well known to appear in two 

 forms — anthedon, mimicking the Danaine Amaxiris niavius, and 

 dabia, mimicking other species of Amaiiris. Mr. Lamborn has 

 shown that these two forms bear a Mendelian relationship to each 

 other, dubia being the dominant. Intermediate patterns occur, 

 although in very small proportions, and it might well be supposed 

 that these are hetei'ozygotes and that they would split up in the 

 next generation. Twice, however, Mr. Lamborn has bred from a 

 slightly intermediate (viz. tending slightly towards anthedon) 



