( Ixviii ) 



P. DARDANUS. — Prof. PouLTON said, in reference to the breed- 

 ing experiments of Mr. Swynnerton and Mr. Lamborn, that at 

 first when we only had before us families of dardanus from the 

 Durban district, it seemed hopeless to expect that the Mendelian 

 relationships would be made out. He had shown some of these 

 families to Prof. Bateson, who agreed that, with three forms of 

 mimetic female and the unknown potentialities of the non- 

 mimetic males, the facts were so complex that a solution was 

 improbable. Some years later Mr. J. C. F. Fryer's success 

 with P. polytes, L., in Ceylon, made the problem appear far 

 more hopeful, and it had occurred to Prof. Poulton that light 

 might be gained by breeding dardanus in parts of Africa where 

 one form was extremely predominant over the others. Although 

 cenea was the commonest form in the extreme S. and S.E. of 

 Africa, hippocoon was even more predominant on the West 

 Coast and in most of the forested areas N. of Natal. In one of 

 these areas — Chirinda in S.E. Rhodesia — offspring had been 

 reared from 19 hippocoon parents by Mr. C. F. M. Swynnerton, 

 as recorded on the present occasion (pp. Ivii-lxiii). All the ofi- 

 spring were hippocoon. Seven families had been reared by Mr. 

 W. A. Lamborn from the corresponding form in S. Nigeria, and 

 in all except the one now recorded, hippocoon offspring and 

 these alone had been obtained. The uniformity of this result 

 suggested that hippocoon was a recessive and that a pre- 

 dominant number of males carried the hippocoon potenti- 

 ality. The same conclusion was reached with much greater 

 certainty when we studied the families reared from females 

 of the rarer forms in the areas where hippocoon was so predomi- 

 nant. These families — 4 in Chirinda and one reared by Dr. 

 G. D. H. Carpenter in Bugalla Island — always contained 

 hippocoon offspring as well as offspring of the female parent 

 form. It is probably safe to assume that the unknown male 

 parent of these 5 families carried the hippocoon potentiality. If 

 the male carried hippocoon as a dominant relatively to the other 

 female forms all the offspring would have borne the appear- 

 ance of hippocoon. The hypothesis that the male parent 

 carried hippocoon as a heterozygote was extremely improbable, 

 because of the great numerical predominance of this form and 

 the relatively few matings that were likely to occiu- with any 



