451 
hidden and the exposed parts had independently proceeded each 
along its own course (p. 31—83), on which the one as well as the 
other could get on at a higher speed and so reach a stage more 
remote from the original common condition. 
From a general point of view I feel inclined to join this opinion, 
but in the case at hand it brings us little light. The difference 
between the covered and the exposed wing-areas in the attitude of 
rest, already slight in the male of pavonia, is quite insignificant 
in the female, as well as in both sexes of pyri and spini. The 
wing-markings on these areas seem not to be influenced to any 
notable degree by the habit of passing the forewings over the greater 
part of the hindwings during day-time. That traces of such an in- 
fluence are still visible in the male of Sat. pavonia, might be 
taken as an indication that the original influence of the said habit 
is now gradually losing its force. 
The highly conspicuous eye-spots in my opinion must have evolved 
from simpler discoidal marks, hand in hand with the above men- 
tioned change in the influence of the resting attitude. This is already 
proved by their very different degree of differentiation in the 
several species of the genus Saturnia and of kindred genera. Eye- 
spots moreover always are special differentiations, secondarily deve- 
loped on the base of a more primitive and simple colour-pattern, 
whose elements have occasioned them by modifications in the original 
shape, colour, size and direction. 
In my previous paper, on the wing-markings of Sphingides, I tried 
to prove this assertion for the case of Smerinthus ocellata, 
in the same way as I formerly did for the Hepialid moth Ze lo- 
typia stacyi. It must however be possible to prove it as well in 
other cases, e.g. for Vanessa io and many other Nymphalids, and 
likewise for Satyrids and Lycaenids. Cynthia for instance shows 
in what way eye-spots and simple spots alternate in the row of 
submarginal markings, and also often how an eye-spot on the superior 
surface is represented by a common one on the underside. The 
difference between the two seasonal forms in the first place depends 
on the contrast in the differentiation of the eye-spots: in the dry- 
monsoon-generation they are scantily developed, in the wet-dito 
highly so. 
Now, do the hybridisations of Stanpeuss throw any light on these 
questions? As far as I can see not much; in general the hybrids 
are intermediate forms, but as to the width of the submarginal 
dark seam, they agree more with pavonia than with spini, and 
assuredly far more than with pvri. 
