85 
mimicking ants with great perfection. The wings are held close 
together on the back so as to be very inconspicuous; the manner 
of walking is quite ant-like, it runs on leaves, or on the tables in 
the houses, so exactly like ants that it requires some knowledge 
of insects to see that it is really a fly, not an ant, and I had some 
amusement in pointing it out to persons having no training in 
natural history; they invariably asserted it to be an ant. 
The very large fly, Mydas, is mentioned by Jacobi!) as a 
fine case of mimicry, it being supposed to resemble one of the 
large Sphegidæ or some other big wasp. I had the pleasure of 
observing and catching a couple of specimens, and, of course, I 
took it at first for a wasp. I would say, however, that, although the 
shape and colour of this fly does certainly recall a big wasp, its 
habits are by no means wasp-like. It does not move the antennæ 
like a wasp; its flight is heavy and noisy. And it is a very clumsy 
animal; when alighting on a thin twig it often cannot hold itself 
upright, but tumbles over, hanging thus under the twig, and it 
then makes clumsy efforts to get up again — like a very poor 
Symnastic. It made the impression of a foolish creature, which did 
not know how to use its good disguise, spoiling it by its clumsy, 
Most wasp-unlike habits. 
Some curious Cicads of the Membracidæ (Spongophorus) with 
very large dorsal excrescenses, proved to be a very fine instance 
of protective resemblance. I saw them often alighting on leaves; 
they always fell on the side and then looked in the most wonder- 
ful way like a small piece of a rotten leaf, of which only the ir- 
regularly anastomosing ribs were left (Fig. 17). I have had no 
Opportunity of consulting the Monograph on the Membracidæ by 
uckton, in which Poulton has given some 
Suggestions as to the meaning of the shapes 54 
and colours of the Membracidæ in the struggle 
for existence (quoted from Jacobi, Mimicry, 
P. 203). I do not know, accordingly, whether i rene 
thi ; 3 å "ig. 17. Two Membracids 
IS observation agrees with the ideas put forth 6 ne genus Spongopho- 
by Pou lton. rus; Sp. GueriniiFaivm (2) 
é to the left, sp. biclavatus 
It was, however, among the butterflies that "gg. 40 the right. 
the most RR observations were made. Natural size. 
) A.Jacobi. Mimikry und verwandte Erscheinungen. 1913. p. 90. 
