41 
I am afraid this is only making the matter worse, and subordinating 
the upperside to the underside with a vengeance. However, no doubt 
coming to further consideration of uppersides, they can easily be re¬ 
established in at least a position of equality. 
Sexual dimorphism. —Now, further, in the development of upper- 
side while supporting its claims to one element, the purposes of 
recognition (similarity with its own species and distinction from other 
species—more or, often, less successful), still another possible element 
must be mentioned as having claims, viz., protection of still further 
extent. Protection and recognition may be in combination as may 
loosely be said to be the case in mimetic arrangements, or they 
may be in apparent opposition, as would probably be considered usual, 
as that the brilliant blue of $ L. bellanjus might be said to be an 
upperside danger. But this action may be less usual than we might 
think, though at the outset, where we have to grapple with the 
phenomena of sexual dimorphism (a striking, widespread, apparently 
nearly inevitable necessity), it might seem that, with the exception of 
warning colours (so lately understood) as at present limited, any sort 
of display could not be an immediate protection as opposed to the 
co-operative or mediate action before mentioned. But we must 
concede to the $s the advantage (necessity?) of being able to be 
inconspicuous when “ on the lay,” or “on the sit,” or copulated (birds, 
beasts, reptiles, fishes, etc., as well as lepidoptera). Obviously, along- 
tailed Japanese cock, a 3 pheasant, or a peacock is ill-suited to sit in 
seclusion. A 2 bellarjus has to be attending to business which carries 
her from place to place for distribution of ova. Inconspicuousness 
may, in different branches of the animal kingdom, be due to differing 
details of procreation. Conspicuous male parents may absolutely aid 
by diverting attention from the 2 . 
The 3 bellanjus may divert attention from the 2 in the act of 
separation when disturbed or at the end of copulation, and even 
in copulated bellanjus in occasional involuntary flight, if the male 
colour shows, it may divert attention by its virtue as a warning colour, 
as will be suggested later, whereas in frogs and toads, with prolonged 
periods of exposure when copulated, sexual dimorphism is at a 
minimum. 
Consp : cuous $ parents in birds may readily divert attention from 
the 2 and the nest, and are as we know, in some species, replaceable 
by batchelors, more readily than are the eggs or young. 
The sexual dimorphism in butterflies means, of course, added 
safety to active hunting 3 in ready recognition of sex of widespread 
unimpregnated 2 waiting. And also added safety, in times of possible 
danger, to the 2 in ready recognition of passing 3 , so that neither 
need unnecessarily expose themselves, in doubtful times, for want of 
sex-recognition. The inverted sexual dimorphism of ianira may be 
a source of safety to the 3 s, which are much hunted at times by 
swallows. But, though of course the usually less brilliantly coloured 
2 is generally considered to be in a condition of greater safety from 
this fact, and from her retiring, slinking, quieter habits, are we 
justified in assuming the amount of danger which is usually attributed 
to the brilliant colouring of a male—such as L. bellanjus, i.e., in 
assuming it to be an unmitigated danger. 
xix. 
