506 Mr. R. Trimen on Mr. Millar's Experimental 
wisdom of not resting content with one test experiment 
only, when its result runs counter to that of a previous 
experiment in the same field. In this case, when the 
numerous progeny of the mima taken in March 1909 
turned out to be without exception of the same form in 
both sexes as the mother, a very imperfect knowledge of 
the actual state of things would have been gained if that 
single experiment of breeding from ova of miina had been 
accepted as conclusive in its result, and so remained 
unchecked by repetition.* 
As indicated briefly in my preliminary note (/. c., p. xv), 
the case of E. wahlhcrgi-mima. agrees with that of another 
Nymphaline butterfly in Natal— Gharaxes zoolina-ne- 
anthcs,\ but at the same time differs very strikingly by 
exhibiting in addition close mimicry of two Avholly dis¬ 
tinct and very differently marked and coloured species of 
tlie protected genus Amauris, and thus presents the first 
recorded instance of hi-sexual mimetic dimorphism occur¬ 
ring within the limits of one and the same species. In the 
Gharaxes mentioned there is no approach to mimetism, 
the colouring and marking in both the zoolina and neanthes 
forms being inconspicuous—especially in the latter—and 
on the underside cryptic, and this makes it difficult to 
discern what the Gharaxes gains by its bi-sexual dimor¬ 
phism ; whereas in the Enralia the advantage of that 
condition in combination with close mimicry of two such 
dominant distasteful Danaines as Amauris niavius domini- 
camis and A. alhimaeulata is manifest. 
In considering the very differing proportion of the two 
forms of Enralia in the respective progenies reared from 
the wahlbergi mother and the two mima mothers by Mr. 
Millar, it is well to bear in mind that in no one of the 
three cases in question is it known to which form the 
* Mr. Millar has presented the progeny resulting from this fourth 
breeding experiment, viz. 8 mima and 3 wahlhergi from ova of a 
single mima, to the unrivalled bionomic series in the Hope Depart¬ 
ment of the Oxford University Museum ; and Prof. Poulton has 
most kindly contributed the excellent photograph of them by Mr. 
Alfred Robinson, which is reproduced in Plate LXIV. 
t See Mr. G. F. Leigh’s interesting accounts in Proc. Ent. Soc. 
Loud., 1908, pp. lxiA% Ixv (with comments by Mr. G. A. K. Marshall, 
Prol. Poulton, and Dr. K. Jordan), recording the breeding ol both 
neanthes and zoolina from ova of a single neanthes, and in op. cit., 
1909, pp. xlix, 1, the converse breeding of both forms from ova of a 
single zoolina. 
