32 



It is of importance to note that the pattern varies somewhat 

 in the different famihes, the first showing an evident tendency 

 towards the enlargement of the principal white patch which 

 spreads over part of both wings. The hippocoon form of the 

 east coast differs from that of the west in the increased size of 

 this patch, corresponding with the difterence between the eastern 

 Amatiris niavius dominicanus and the western Amauris niavius 

 niavius. It is therefore of much interest to find on the west 

 coast a hereditary tendency towards slight changes in the size 

 of the patch. It is reasonable to suppose that by selection 

 operating upon such small hereditary differences the eastern 

 hippocoon could be derived from the western, and vice versa. 



In the southern section of the tropical west coast the female 

 forms become more varied, and we again meet with planenwides, 

 doubtless continuous, across the great tropical forest, with the 

 assemblage of the same forms in Uganda, and corresponding 

 with the co-existence of the appropriate Planema models over 

 the whole area. The single specimen before you from Angola is 

 of interest as being probably the first example in any European 

 collection. It was collected in 1873 by W. Rogers.^ The 

 relatively frequent occurrence of niohe also probably corresponds 

 with the presence of its Planema model. 



We now return to Nairobi, the central point of the great 



delivered Mr. Lamborn has bred three more famihes, containing respec- 

 tively 14, 7, and 6 females, all hippocoon. He also obtained a few eggs 

 from a dionysus form, but unfortunately these failed to hatch. I sug- 

 gested to Mr. Lamborn that it would be of great interest to ascertain the 

 effect of artificial cold during the pupal stage of the female forms. In 

 his locality, Oni, seventy miles east of Lagos, it was impossible to keep 

 up a continual supply of ice, but the first of the families mentioned in 

 this footnote was exposed for a few days to a temperature (about 50° F.) 

 which for that part of the world would be unusually low, and it was 

 interesting to observe that 4 out of 14 of the females possessed slight but 

 distinct traces of the " tail " of the male hindwing. Of the other five 

 families only one included females with traces of the " tail " — two similar 

 to the Î $ mentioned above and two others with slighter indications. 

 Hence it is not unlikely that an effect was produced by the artificial cold. 

 It is to be hoped that this experiment may be repeated in a locality more 

 favourably placed for the maintenance of a low temperature. See Proc^ 

 Ent. Soc, 1912, pp. cxxxi-cxxxiv. 



^ Proc. Eni. Soc, Lond., 1903, pp. xxxix-xli. 



