suggestions as to insect colours and patterns. 571 
W. J. Kaye if he can remember the colour of the 
flowers visited by the black, cow-red, and yellow Melinxa 
group and its mimics in British Guiana, and he tells 
me they are either white or cream-coloured. Further- 
more, Mr. Thayer treats this group as though it 
were uniform throughout tropical South America, dis- 
regarding the extraordinary changes of colour and 
pattern undergone by its representative species as we pass 
from one part of the Neotropical region to another. It 
is almost inconceivable that the following features, which 
are characteristic of whole groups in particular areas, can 
be due to the special flowers of those areas. The barred 
form of Central America, Colombia, and Venezuela, the 
black hind-wing of the Guianas, the bright yellow band of 
Eastern Brazil, the chestuut ground-colour of Ega on the 
Amazon, the black marked fulvous of the Napo River, 
passing on into the black forms with fulvous marks whieh 
constitute so large and characteristic a group in Ecuador, 
Peru, and Bolivia. In all these cases, nothing short of 
actual evidence on the spot can warrant the improbable 
suggestion that we are dealing with syncryptic groups, 
changing as the species of flowers are replaced by others 
in passing from one district to another. 
Moreover, the theory of a syncryptic resemblance to 
flowers fails to account for certain broad characteristics of 
the groups in question, which on the other hand receive 
a ready explanation on the theory of common warning 
(synaposematic) coloration. These are (1) the predomin- 
ance of forms belonging to the sub-families Jéhomiine, 
with the allied Danaing, and Heliconine, with the allied 
Acrvin# ; (2) the fact that the predominant members of 
the chief groups in all the other tropical parts of the 
world are also contributed by the Danainx and Acrvine : 
(3) the flaunting flight, exposure at rest, and general 
want of alertness exhibited by the species of these sub- 
families as compared with others: (4) the more or less 
exact similarity of the pattern on the under to that on the 
upper surface, an arrangement comparatively rare in other 
Rhopalocera: (5) the experimental evidence of the un- 
palatability of these very sub-families to a large number 
of the enemies of insects. 
Hence, until positive evidence is obtained on the spot 
in favour of Mr. Thayer’s suggestion of syncryptic resem- 
blance, I must regard such an interpretation as highly 
