522 Dr. F. A. Dixey On the Diaposematic 
greater needs—a rule which holds good not only in 
mimicry but also in other kinds of defence. Another 
point worthy of notice is, that as shown by Figs. 6 and 7, 
compared with 6A and 7A, the resemblance borne to each 
other by the upper surfaces of the two insects does not 
extend to the lower. This seems to favour the view that 
the enemies in this instance guarded against are such as 
attack butterflies on the wing rather than at rest. 
But the most interesting feature in the case is the 
evidence it affords of diaposematism, or the interchange of 
warning characters between mimic and model. In his 
original description of H. corva, Wallace drew attention to 
the fact that this form possesses a black border to the 
hind-wing, “much wider and more defined than in the 
allied forms” (Trans. Ent. Soc. Lond., 3rd Series, IV, 
1867, p. 339). This dark border, as can be seen in Plate 
XXXI, figs. 3-6, is present in both sexes; it 1s formed 
in the female by the fusion of the submarginal row 
of V-shaped spots seen in Fig. 1 with the actual dark 
edging of the wing. A somewhat similar feature, though 
less pronounced, occurs in H. lichenosa, Moore, from the 
Andaman Islands; but in the ordinary allied forms known 
as Huphina nerissa, H. phryne, H. copia, etc., it does not 
exist. A comparison of Figs. 1 and 2, which represent 
the female and male respectively of the typical H. phryne 
of continental India, with the figures of H. corva in the 
same Plate, will show the difference referred to by Wallace. 
This difference is even better marked in the dry-season 
form of H. phryne than in the wet, the latter being the 
phase here figured. 
Now it is in large measure to the presence of this dark 
border on the hind-wing that H. corva owes its correspond- 
ence in aspect with J. baliensis. It is of course open to 
any one to assert that the dark border is merely an acci- 
dental feature in H. corva without any special significance. 
But when we consider that this feature is practically 
restricted to that form of the H. nerissa group whose 
range overlaps that of the Jzias which it so closely re- 
sembles, the conclusion seems at once to suggest itself 
that the presence of the dark border in H. corva is the 
result of a mimetic approach to the other insect. In this 
respect, then, the Huphina has acted as the mimic and 
the Jzias as the model. If, however, we turn to the fore- 
wing, we find the process reversed; here it is the Jzias 
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