244 The Naturalist in Nicaragua 
species that resembles a wasp moves its antenne restlessly, 
like the latter insect. 
The movements, as well as the shape and colour of the 
insect imitated, are mimicked. I one day observed what 
appeared to be a hornet, with brown semi-transparent wings 
and yellow antenne. It ran along the ground vibrating its 
wings and antennez exactly like a hornet, and I caught it in 
my net, believing it to be one. On examining it, however, 
I found it to belong to a widely different order. It was one 
of the Hemiptera, Spznzger lutetcornits (Walk.), and had every 
part coloured like the hornet (Priocnemis) that it resembled. 
In its vibrating, coloured wing-cases it departed greatly from 
the normal character of the Hemiptera, and assumed that 
of the hornets. 
All the insects that have special means of protection, by 
which they are guarded from the attacks of insectivorous 
mammals and birds, have peculiar forms, or strongly con- 
trasted, conspicuous colours, and often make odd movements 
that attract attention to them. There is no attempt at con- 
cealment, but, on the contrary, they appear to endeavour to 
make their presence known. The long narrow wings of the 
Heliconii butterflies, banded with black, yellow, and red, 
distinguish them from all others, excepting the mimetic 
species. The banded bodies of many wasps, or the rich 
metallic colours of others, and their constant jerky motions, 
make them very conspicuous. Bees announce their presence 
by a noisy humming. The beetles of the genus Calopteron 
have their wing-cases curiously distended, and move them up 
and down, so as to attract attention; and other species of 
Lampyride are phosphorescent, holding out danger signals 
that they are not eatable. The reason in all these cases 
appears to be the same as Mr. Wallace has shown to hold 
good with banded, hairy, and brightly coloured caterpillars, 
These are distasteful to birds, and, in consequence of their 
conspicuous colours, are easily known and avoided. If they 
were like other caterpillars, they might be seized and injured 
before it was known they were not fit for food.t 
1In a paper on ‘“ Mimicry, and other Protective Resemblances 
amongst Animals,” first published in the Westminster Review, July 
1867, afterwards in Natural Selection, Wallace has elaborately dis- 
cussed this question. My observations are supplemental to his and 
to the original ones of Bates. 
