39 
ami of extent of silver occurs, beyond what is noted above, whereas 
the uppersides are commonly decidedly variable. Whether or no one’s 
experience is exceptional, it remains that three or four or more quite 
different forms of upperside aberrations in euphrosyne and selene are 
accompanied by normal undersides fairly commonly, and when accom¬ 
panied by underside aberration, of any extent, the latter is almost 
always of one form only, in differing degree. 
Mutiple adaptability of undersides. —The extraordinary contrast 
between frequency and variety of advanced upperside variations, 
and the rarity of underside variations, and their want of scope may 
be much more marked in JJrenthids than in other butterflies, but I 
think, especially if the crypton bo excepted, there is no doubt that 
it is true in differing degrees of all, or nearly all, butterflies ; and this 
suggests the importance of the view that aberrations of the undersides, 
as well as the usual forms, need to conform to the surroundings, or at 
least to be in harmony. This conception having led to several years 
of steady collecting of especially, among many species, the undersides 
of “ blues,” has led to the conviction of the multiple adaptability of 
each underside to many forms of surroundings in their habitats when 
the imagines rest or sleep or attempt elusiveness. The hyeacnids of 
chalk, for instance, resemble grass blooms, plantain heads in bloom, 
chalk patches or gravelly patches, and many other natural objects ; 
aeyon, especially in the $ , is protected by resemblance to heathers, 
last year’s blooms, old “ knob heads,” rush blossoms and many 
forms of soil, and many others as A. selene and M. athalia excellently 
resemble bits of dead bracken, heads of plantain past their prime, 
dead blooms of l 1 loscucuH, tufts of Melampyre, blooms of rushes, etc. 
The colour of .S', semele is adaptable to simulating many soils, and lime¬ 
stone, and chalky patches, burnt juniper, and dead wood or living 
bark. I remember once, on top of Folkestone bills, noticing the 
outline of a semele against the sky as it rested on the post of a wire 
fencing, and on careful searching found numbers of pairs on other 
posts and single specimens, all excellently protected by their under¬ 
side coloration, except when seen in profile against the light of the 
sky of the North. 
The similarity of undersides of L. aryiolus to bright reflections 
from Holly, Ivy, Portugal laurel, Rhamnus, Dogwood, and Privet seems 
almost to suggest its association with these plants from this 
circumstance, and that secondarily, it uses them as larval foods ; 
aryiolus, moreover, is by no means too conspicuous on pale and white 
blooms such as bramble blossom, which it loves. 
The underside of S. malrae resting excellently reproduces same 
effect as dead plantain heads or knob heads, or old fruit of solitary 
thistle and grass and rushes; in fact of living and dead herbage 
generally and varying soils. 
And to take one more familiar example, the likeness of A. carda- 
viines resting, to cow parsley blooms and buds, is easily extended by 
observation to Cardamine bloom, Alliaria, and many Cresses in bloom, 
Dandelion “ clocks,” and young shoots of Umbelliferac. Perhaps the 
fact that cow parsley is so well known and often quoted in this 
matter, is a proof that others are a greater protection because less 
often “found out” in their protecting action. In fact, one wonders 
xix. 
