BEDROCK 



my friend, Rev. K. St. Aubyn Rogers, who has done so much for the 

 Oxford University collections, informs me that in parts of the 

 Mombasa coast district, where Amauris dominicanus occurs, but 

 echeria and its ally are wanting, the wahlbergi form is common, but 

 mima never seen. Moreover, about a hundred miles to the west the 

 latter model again becomes common and mima at once reappears. 



When Mr. A. D. Millar proved that wahlbergi and mima were 

 dimorphic forms of one species, it became obvious, as I had suggested 

 in 1902,* that their respective Western representatives anthedon 

 and dubia are also mimetic forms of one species. Furthermore, 

 in Uganda these Eastern and Western forms meet, and there can 

 be little doubt, as Dr. Karl Jordan has pointed out, that we are 

 concerned with a vast continuous interbreeding community, — a 

 single species with corresponding forms modified by mimicry on 

 the opposite sides of the Continent. The far-reaching interest 

 of this conclusion made it all the more important to test the 

 western forms by breeding. A set of these mimics (Figs. 6 — 10) 

 with their models (Figs. 1 — 5) captured by Mr. Lamborn in the 

 neighbourhood of Oni Camp seventy miles East of Lagos is shown 

 on Plate III. Anthedon (Fig. 6), the western form of wahlbergi, is 

 the mimic of niavius (Fig. 1), the western form of dominicanus 

 (Plate I., Fig. 2) : dubia, on the other hand, although obviously 

 corresponding with mima, appears in three forms (Figs. 8, 9 and 10) 

 mimicking three species of Danaince (Figs. 2 — 5). The first form 

 (Fig. 8), with a brown shade bordering the white patch of the hind 

 wing, mimics Amauris egialea (Fig. 2) ; the second, more strongly 

 marked with white, mimics the commoner form of Am. psyttalea 

 (Fig. 3) : the third, with the white markings reduced, especially in 

 the hind wing, mimics Am. hecate (Fig. 5) and a rarer form of Am. 

 psyttalea (Fig. 4), which is itself a mimic of hecate. 



In 1911 and 1912 Mr. W. A. Lamborn bred twenty families, 

 containing over 1,400 offspring, from known female parents, some 

 of them anthedon and others including all the above-mentioned 

 forms of dubia. Anthedon behaves as a recessive, four times pro- 

 ducing al\-anthedon, once all-dubia, and three times mixed 

 families as it would do if it had been mated with recessives, a 



* Trans. Ent. Soc, p. 492. 



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