1260 
a majority of differently coloured ones, and gives rise to the supposition 
that this green has arisen as an adaptation to surroundings, and in 
so doing has obseured an older and more elaborate colour-pattern. 
This is a general rule, applicable not only to Lepidoptera, but 
likewise to other insects, and even to all groups of animals. Turning 
our attention to the silverv marks of Leto, we meet them in other 
genera of Hepialids as well, though smaller in shape and number, 
e.g. Hepialus, Phassus, Phassodes, Charagia, Hepialiscus, Pielus. 
For here they occur in corresponding places, and often show the 
same arrangement in transverse rows. Moreover on comparing the 
different species of the above-named genera and looking over series 
of specimens, we become convinced that the silvery shine of these 
spots is not essential. It varies not only with the species, but even 
with the sex and in the individuals. Ch. ramsayi for instance, 
especially in the female sex, shows a good number of well-developed, 
very conspicuous silvery spots, the most so in the variety chryso- 
mallon, in which again the ground-colour is brown instead of green, 
and devoid of all remaining primary markings. But the male sex 
possesses fewer and smaller silvery markings, and this is also the 
case with Ch. mirabilis # to an even greater extent. Yet the ten- 
dency to silvery lustre must be present there as well as in the », 
for the smaller groups of lustrous scales occur in just the same 
places as in the latter. 
In the female of mirabilis on the contrary, this tendency seems 
at first sight to be altogether absent. Yet the place of the lustrous 
spots is occupied by markings of a special character, viz. dark spots, 
composed of a deep-blue dumbbell-shaped centre situated between 
two brown rounded blotches. Perhaps the fact that the metallic blue 
gives a sharp white image on the photographic plate, and that the 
same is the case to a less degree with the brown blotches, is not 
without deeper significance, as it gives evidence that these two 
colours emit active chemical rays. 
Sundry other species of Charagia have the lustrous spots of some 
individuals replaced in others by dark brown blotches (Ch. virescens, 
eximia). The same occurs in species of other genera, as is shown 
by the series: 
Phassus chamyli, purpurascens, giganteus. 
Phassodes guthrei ¢, odorivalvula #, vitensis, rewaensis, nausori £. 
Pielus hyalinatus, var. leucochiton &. hyalinatus © var. bursa. 
Trictena labyrinthica ¢ & §. 
Hepialus humuli ¢ (totally lustrous white}, fusconebulosus, hectus, 
humuli ¢. 
