342 Mr. Grote on the Changes in the Wings of Butterflies. 
Variation in the Course of Veins. 
In making preparations of one and the same species 
I have usually found little variation in the butterflies, but 
my experience is limited to from two to six individuals ; 
in some cases I have contented myself with one prepara- 
tion, but usually I have made a second and, if it quite 
agreed, have gone no furtherin my examinations. Sexual 
characters I found to exist only in the swollen veins of 
the Meadow-Browns and Potamis. But in the moths I 
have found some variation which lies in the general 
direction of the changes which are indicated above. The 
most surprising to me was that, among five preparations 
of Copismer inthus ocellatus, I foul one female in which 
vein iv; did not emerge from the radius immediately 
beyond the cross-vein, but from the cross-vein itself. 
This was a generalized individual]. The usual position of 
this vein is from the radius at a greater or less distance 
from the cross-vein. Another female had an intermediate 
position for vein iv; which, on the primary at least, 
seemed to occupy precisely the angle of the junction. 
These characters cannot be expected to be other than 
plastic, and it is sufficient for our theory if the variation 
takes the same line, within the assumed limits of one, 
species, as that which it exhibits in different species. 
Undoubtedly in the primitive Smerinthus the origin of 
vein iv; was from the cross-vein, from which it has been 
removed in most of the forms, permanently as it appears, 
to the radius. 
The second kind of variation consists in the sudden 
appearance of short spur-hke processes arising from the 
veins. I found such a prong issuing from vein ill, in a 
female Endromis. Another case occurred with a female 
Smerinthus 11 which vein vg showed a curved prong 
urising near the base. In the process of individualiza- 
tion the mould sometimes breaks. 
In conclusion, I would urge the method of photo- 
graphy in picturing the venation. The published draw- 
ings are frequently inaccurate and insufficient for purposes 
of “study : 
