112 THE ENTUMOJ.OGISt's KKUtJKD. 



" Look here, friend, wake up and be ott' as quickly as ever you can, or 

 a fearful beast of prey will have you in a moment," and the moth 

 certainly followed the advice with success. The truth probably was 

 that flies, which were abundant enough, often select little prominences 

 for settling on, and these happened to think the moths were such 

 favourable resting-places, and the flight of the moth probably startled 

 them as much as it annoyed me. 



On our way home at Guethary (France) we met with a most 

 striking case of what appeared to be homoeochromatism, whether it 

 be explained as a case of Miillerian resemblance or otherwise. The 

 facts must be w^ell known, but I do not know that any attention has 

 been called to them from this or any other points of view^ The three 

 butterflies involved are Satijnis dri/as, (Joenani/nip/ia oedijms, and 

 Heterujitenis morphens. These butterflies are all of a sooty dull black 

 above, and have much the same black appearance on the wing. At 

 Guethary they flew together in very restricted little bogs or swamps — 

 swamps at the upper ends usually of the little streams of rarely more 

 than three or four acres in extent, and lying in very sheltered hollows, 

 perhaps lOOtt. below the general upper level. They were the only 

 butterflies in these swamps, and they did not occur outside them. If 

 really minute accuracy is required, as it ought to be, this broadly true 

 statement must be modified by saying that S. dryas did fly a little way 

 up the slopes bounding the bogs, and one or two were even seen on 

 the upper levels. These were all, however, occasional stragglers, 

 possibly because the swamps were so small as to be easily left by so 

 large a butterfly. N. dnjas, however, as well as the other two, were 

 often seen to get anxiously back to the bog if driven by the collector's 

 net (or otherwise) only a few feet up the side slopes. Of other 

 butterflies, ( 'olia>i ednsa flew across the bogs as it does across 

 anything, and Breiitliis eiiphrasj/ue, ( '(lejioiiipiipha arcaniiis, Hesperia 

 aylrantis aftbrded an occasional example. Many butterflies were 

 abundant all around. Taking this to be a Miillerian association, 

 it presents three species that might be grouped together, not 

 only by the entomologist, but by a bird or any other predaceous 

 animal, as a group dift'erent and easily distinguishable from 

 everything else about. It dift'ers from the Neotropical Miillerian 

 associations of butterflies, in its members having merely a broad but 

 unmistakable resemblance, and none of the minutely detailed identity 

 of size, colour, and markings seen in the Heliconine groups. At 

 Guethary butterflies of many species abounded at this time, and any 

 bird, say, could catch plenty without trenching on these bog species, 

 and making it not worth its while to discriminate between them. 

 Were other butterflies scarce, and one or other of these bog species 

 edible, a bird would have no difticulty in ditterentiating them — 

 .S. dryas by its size, H. niurpheiia by its hopping flight and underside 

 shown at each skip, etc. That they were protected seemed probable 

 from their lazy flight, rendering them of very easy capture, very 

 difterent, for example, from Satynis aretlmsa, which was abundant 

 close by, but very difticult to take. They could fly if they liked — 

 (.'. oedipiis was the weakest, but S. dryas could go powerfully if 

 frightened, and H. nwrplHiia possessed to the full the skipping faculty 

 for a mysterious disappearance. My experience of these three butter- 

 flies certainly does not present them as always associated. Last year 



