154 LOWER AMAZONS—OBYDOS TO MANAOS. Crap. VIL. 
deceptive resemblance to the species of working bee, in whose nest it 
deposits the egg it has otherwise no means of providing for, or when a 
leaping-spider, as it crouches in the axil of a leaf waiting for its prey, 
presents an exact imitation of a flower-bud ; it is evident that the benefit 
of the imitating species is the object had in view. When, however, an 
insect mimics another species of its own order where predaceous or 
parasitic habits are out of the question, it is not so easy to divine the 
precise motive of the adaptation. We may be sure, nevertheless, that 
one of the two !s assimilated in external appearance to the other 
for some purpose useful—perhaps of life-and-death importance—to the 
species. I believe these imitations are of the same nature as those in 
which an insect or lizard is coloured and marked so as to resemble the 
soil, leaf, or bark on which it lives; the resemblance serving to conceal 
the creatures from the prying eyes of their enemies; or, if they are 
predaceous species, serving them as a disguise to enable them to 
approach their prey. When an insect, instead of a dead or inorganic 
substance, mimics another species of its own order, and does not prey, 
or is not parasitic, may it not be inferred that the mimicker is subject 
to a persecution by insectivorous animals from which its model is free ? 
Many species of insects have a most deceptive resemblance to living 
or dead leaves; it is generally admitted, that this serves to protect 
them from the onslaughts of insect-feeding animals who would devour 
the insect, but refuse the leaf. The same might be said of a species 
mimicking another of the same order: one may be as repugnant to the 
tastes of insect persecutors, as a leaf or a piece of bark would be, and 
its imitator not enjoying this advantage would escape by being decep- 
tively assimilated to it in external appearances. In the present instance, 
it is not very clear what property the Callithea possesses to render it 
less liable to persecution than the Agrias, except it be that it has a 
strong odour somewhat resembling Vanilla, which the Agrias is destitute 
of. This odour becomes very powerful when the insect is roughly 
handled or pinched, and if it serves as a protection to the Callithea, it 
would explain why the Agrias is assimilated to it in colours. The re- 
semblance, as before remarked, applies chiefly to the upper side; in 
other species * it is equally close on both surfaces of the wings. Some 
birds, and the great ASschnz dragon-flies, take their insect prey whilst 
on the wing, when the upper surface of the wings is the side most con- 
spicuous. 
In the broad alleys of the forest where these beautiful insects are 
found, several species of Morpho were common. One of these is a 
sister form to the Morpho Hecuba, which I have mentioned as occurring 
at Obydos. The Villa Nova kind differs from Hecuba sufficiently to be 
considered a distinct species, and has been described under the name of 
M. Cisseis ; but it is clearly only a local variety of it, the range of the 
two being limited by the barrier of the broad Amazons. It is a grand 
sight to see these colossal butterflies by twos and threes floating at a 
great height in the still air of a tropical morning. They flap their wings 
only at long intervals, for I have noticed them to sail a very considerable 
distance withouta stroke. Their wing-muscles, and their thorax to which 
* Agrias Hewitsonius and Callithea Markii. 
