EHOPALOCERA. 
35 
attack. These lucky exceptions to the common condition of being 
hunted down by hungry devourers are the Danaince and Acrceince, 
Sub-Families of Nymphaliclce ; ^ and they owe their immunity to their 
being malodorous and unpalatable as food, and to their evidently being 
recognised as uneatable by insectivorous animals. It is most interest- 
ing to find these protected butterflies accompanied, wherever they are 
prevalent, by species of different Sub-Families or Families which closely, 
or even exactly, resemble them in form, colours, and markings, though 
quite diverse in structure. The first entomologist who carefully ob- 
served these " mimicries " in Nature, and arrived at a clear and 
reasonable explanation of their meaning and origin, was Mr. H. W. 
Bates, F.R.S., whose paper on the subject was read before the Linnean 
Society of London in 1861, and subsequently published in the Trans- 
actions (vol. xxiii.) of that body. Mr. Bates dealt with the very rich 
material yielded by the butterfly fauna of Tropical South America, and 
showed that while the models (protected species of Danaince) were 
most abundant and presented the ordinary fades of their family, the 
mimickers were rare, and departed very widely from the appearance of 
their nearest allies ; that the latter frequented the same spots as their 
models, often flying among them ; and that the resemblance in life 
was so exact as constantly to deceive his own experienced sight. He 
observed that the very conspicuous and slow-flying Danaince were not 
pursued by any of the ordinary enemies of insects to which they would 
have fallen an easy prey, and detected the reason for this security in 
the peculiar smell which they emitted, and thus indicated the obvious 
advantage it would be to butterflies not so defended to resemble 
Danaince closely enough to be mistaken for them, and so passed over 
as uneatable. Demonstrating the identity in kind of these mimicries 
with the protective resemblances to inorganic and to vegetable forms 
so prevalent in Nature, he traced them similarly to the long-continued 
action of natural selection, the chief operating agents being insecti- 
vorous animals, which would continually destroy all those individuals 
of the mimicking species least resembling those which are exempt 
from persecution. Mr. Bates gave a list of no fewer than thirty-six 
cases of mimicry known to occur among Tropical- American butterflies, 
and in thirteen of these even the remote Moths (of the groups Castnim 
and Bonibyces) supplied instances of mimicry. In one of these cases, 
the Danaine Metlwnct Fsiclii is imitated by two other DanaAnce of the 
genus Itwia,^ by the Pierine Leptalis Orise, and by two Moths ; while 
^ There are also some similarly protected species among the Heliconince and Papilionince ; 
and these too have accurate imitators in other butterflies. 
^ These cases of apparent mimicry within the limits of the protected group itself present 
much difficulty. It might be supposed that the mimickers in these instances had for some 
reason failed to acquire the distastefulness of their kindred, but this has not yet been shown 
to be the case. Dr. Fritz Mliller, Mr. Wallace, and Mr. Distant have discussed the ques- 
tion in Kosmos (1879-81) and in Nature (vol. xxvi.) ; and Mr. Meldola {Annals and Mag. 
Nat. Hist., December 1882) has published an interesting summary of the discussion, in 
