332 THE PLACE OE MIMICRY 



)iinae extensively mimic each other, and are extensively 

 mimicked by other Lepidoptera. The l/cliconiiiac which 

 resemble the ItJiouiiinac belon^^ to the same group as 

 those which resemble other Hcliconi)iae. The likeness 

 is even closer in some pairs made up of Heliconines 

 than in any made up of an Ithomiine and a Heliconine. 

 There is no good exami)le of Procr)plic colouring in the 

 whole Sub- P'amily, and the Ileliconine tyjjes of Apose- 

 matic colourini* are far more <'larino- than those of the 

 Itkoniiijiac, When, however, we in(]uire into the relative 

 numbers, it is seen at once that the Mclijiaca as an adver- 

 tisement is hundreds of times as efficient as the Ilcliconiics, 

 because it is hundreds of times as numerous in the perfect 

 state. With Mr. Kaye's kind help I obtained two days' 

 captures of butterllies from the locality near the Potaro 

 River, British Guiana, where this wonderful Miillerian 

 combination has been chiefly studied. It was arranged 

 that butterllies were to be taken as they came, without 

 any selection. On the first day, August 28, 1903, just 

 323 butterflies were captured, of which 253 wqvq Alciinaea 

 m)Lcmc\ while 2 were Hcliconifiac — i Ilcliconius vctusHis, 

 and I Eiicides 7i{(^ro/uha. Of these, the first-named very 

 jjerfectly resembles the dark-hind-winged forms of the 

 Mc/iiuna, while the Eticidcs is a far more outl) ing member 

 of the combination. On the second da}', P^ebruar)- 23, 

 1904, out of a total of 325 butterflies, 220 Mclinaca nnuDic 

 were taken, but not a single Heliconine.^ Mr. Kave's 

 experience, extending over man)- years, (juite coniu'ms 

 the extraordinary difference in numbers which was shown 

 by the results of these two days' captures. It may be 

 argued that the very numbers of the A/ch'naca imi)ly a 

 higher degree of unjjalatabilit)', but this is by no means 

 necessarily the case. Relative numbers are determined 

 by many other causes, such as fecundit}', attacks (chiefly 

 parasitic) in the earlier stages, <^c. 



We are led to conclude that during the period of gradual 

 approach the varieties of H. mcniata which were most 

 conspicuously different from the pattern of Mclinaea 

 inncme suffered most, upon the whole, from experimental 



^ Proc. Eni. Soc, Lofid., 1906, p. Ixi. 



