Ce xc) 
butterflies of both sexes is during courtship and pairing, 
when they are less on their guard than at any other period, 
and those actually paired (unless very well concealed by close 
resemblance of their underside to the immediate surroundings) 
have little chance of escape.* Col. Swinhoe has mentioned 
to me that birds often do not seem inclined to take the 
trouble to give chase to flying butterflies, but sit merely 
watching them, and this is in support of the view that they 
more frequently adopt the easier plan of attacking them when 
feeding, settling. or at rest. The frequency of the cases 
where mimicry is confined to the female points with some 
significance to the probability that persecution is more 
directed against that sex than against the male. 
(s.) The presence of malodorous juices in many insects is 
a matter of common observation, and is a protective property 
possessed by several entire groups, especially among the 
Lepidoptera and Coleoptera. There is abundant evidence as 
to the prevalence of these secretions, and among the Lepido- 
ptera they are particularly developed in the butterflies of the 
sroups Danaine, Neotropine, Acrzeine, and Heliconine, and 
also in some Papilionine, as well as in many moths of the 
eroups Agaristidee, Chalcoside, Arctiidae, Lithosiide, ete. 
The strength of the disagreeable odour emitted is in some 
species very great ; + Seitz, for instance, mentioning that the 
smell of the South-American Heliconius besckei and Fueides 
aliphera extends over a radius of several paces, and Wood- 
mason and De Nicéville testifying to the same effect as 
regards the Indian Papilio philowenus and allied forms. 
When molested many of these offensively-smelling species 
exude drops of a yellow or whitish fluid which leave on any- 
thing they touch a stain and odour difficult to remove, as I 
have experienced in the case of the Mauritian “uplwa euphone, 
the South-African Danaine and ‘Acreine, and various 
South-African Agaristide, Glaucopide, and Arctiide. 
The origin and manner of acquisition of these unsavoury 
* Tt is not improbably in these circumstances that the imperfectly 
mimetic but still ‘‘ warning ’’ underside of the male in Perrhybris becomes 
specially serviceable (Cf. Dixey, Trans. Ent. Soc., 1896, p. 71). 
+ Cited by Haase, /. ¢., i1., p. 101. 
