88 
its wings, unessential for the flight. Also, as 
pointed out by Marshall") the butterfly darts 
off in a direction unexpected by the enemy, 
that takes the tail end for the head, which 
must help the butterfly to escape. 
The remarkable design on the underside of 
Fig. 18. Thecla phaleros the wings in Thecla battus and related forms”) 
SS Sign stper mus — black and white bands, broad at the anterior 
show the outturned lobe edge of the wing, narrowing towards the tail 
KR RS end, those on the hindwing being in direct 
figure. continuation of those of the forewing — has, 
evidently, a special meaning. Ås seen in the figures 3, 6—8, PI.I, 
they all converge towards the false head, with the result that 
the eye is involuntarily directed towards this spot. —— This is a 
curious analogy to the honey guides in flowers. 
In Thecla marsyas Cram. (PI. I, Fig. 12) there is no special 
design on the underside of the wings; still the "false head" is. 
exceedingly conspicuous. Whenever I saw this species I could not 
help thinking that the disguise — if we may call it so — was 
really overdone. In some of the smaller, simpler forms there aré 
lines or streaks, which may perhaps also serve the purpose of 
directing the eyes towards the false head. It seems also to be a 
general rule in the Thecla's that the hindpart of the hindwings is 
brighter coloured than the rest of the underside, which must, evi- 
dently, also serve to direct the attention towards the false head. 
While there can be no question of the meaning of the double 
head of these butterflies, the great question, of course, remains: 
does it really work after the intention? Although I have paid very 
much attention to this question, I have never succeded in finding 
any direct evidence for it. Not one specimen was observed with 
the false head partially or completely bitten off. Possibly, on the 
small island, where my observations were made, there are not so 
end 
2) e A.K. Marshall. The Bionomics of Souh African insects. Trans. 
t. Soc. London. 1902. p. 375 
) Babided Thecla battus and phaleros I have observed at least one more 
species, perhaps two, with the same remarkable design of the underside, 
and I cannot doubt that all the species with this design will prove to have 
the same habit, the design working in the same way 
