243 ZOOLOGY. 



formerly believed to be covered by the former theory. Thus, Dr. F. A. 

 DIxey, of Oxford, has recently shown that Sonth American i/eZ«co/ii«« are 

 affected by the color of certain Pierince which have hitherto been looked 

 upon as true Batesian mimics of the former. 



The old-world nymphaline genus Hypolimnas has been regarded as one 

 of the best examples of mimicry, but an unbiassed examination leads to 

 the opinion that it affords a case of Miillerian rather than Batesian resem- 

 blance. 



In India the female of the common species H. bolina resembles Euplcea 

 core while the male is a dark butterfly with a large white spot, shot 

 with blue, on each of the four wings. Throiigiiout the Malay Archipel- 

 ago representative species occur with males like that of //. bolina and 

 females resembling the local Euploeas. Occasionally, as in Ke Island and 

 the Solomons, species of the genus occur in which the male as well as the 

 female resembles a JEuploea. In Fiji the male is as in the Indian species 

 while the female is extremely variable, ranging from forms like the male 

 through intermediate varieties, to be brown and straw-colored individ- 

 uals. The Euploeas of Fiji are not sufficiently known, but it is very 

 improbable that all the forms of the female Hypolimnas are mimetic. A 

 still more instructive case is that of the nerina form of female found, 

 with a male like that of H. bolina, in Australia, Celebes, New Guinea, and 

 other E. Indian Islands and in many of the Polynesian groups. 



This conspicuous and abundant butterfly has, in addition to the four 

 white-and-blue spots of the male, a large reddish brown patch upon each 

 fore-wing. This well-marked form resembles no other butterfly except 

 the Danais chianippe of Celebes, and, as this latter appears to be very 

 rare, it is far more probable that the resemblance has come from the other 

 side, and that the Danais has approached the Hypolimnas. 



In Africa the sub-genus Euralia is represented by several species which 

 resemble in both sexes species of the P^thiopian Danaine genus Amauris. 



Finally there is the well-known and widespread Hypolimnas missippus 

 wliich accompanies Limnas chrysippus throughout its range; while the 

 female of the former resembles the latter very closely. In this case it is 

 certain that we have to do with no struggling hard-|tressed form, for the 

 Hypolimnas has recently established itself in some of the West Indian Isl- 

 ands and in Demerara — localities in which its model, L. chrysippus, is as 

 yet unknown. 



To sum up — the genus Hypolimnas is distinguished amon<r nymphaline 

 genera for the extent to which its numerous and widespread species re- 

 semble the local distasteful forms of Euplreinse or Danainse. 



Upon the older theory of Bates this would be explained by supposing 

 that the «enus is very hard-pressed in the struggle and has thus been 

 driven to mimicry almost everywhere. Upon the newer Miillerian theory 

 it is supposed that the genus is distinguished among nymphaline genera 

 by some special defence, probably in the way of taste or smell or indi- 

 gestibility, and that it has been to its advantage to adopt the advertise- 



