MAYER: COLOR AND COLOR-PATTERNS. 183 
England, ealled attention to the following faets: the transverse 
series of dark spots so often seen in the body of the wings of 
Lepidoptera are invariably placed in the interspaces between the 
longitudinal veins, never upon the veins themselves, excepting 
only in rare instances, where the spots occur at the extreme margin. 
Ile also pointed out that in many types of moths all differentiation 
in coloring has been greatly retarded, so far as the hind wings are 
coneerned, by their almost universal concealment by day beneath 
the overlapping front wings. In these cases “ the simplest departure 
from uniformity consists of a deepening of the tint next the outer 
margin of the wing." It is but a step from this condition to a 
band of dark color or a row of spots parallel with the margin. This 
» 
explains why the transverse style of markings, for the hind wings 
at least, is so common, Scudder showed that “the number of 
instances, in butterflies, in which similar markings appear in the 
same areas of the two wings, and in the same relative position 
in these areas, is far too common to be a mere coincidence. It is 
most readily traced in the disposition of the ocelli, which are very 
apt to be similar in size and perfection, and to be situated between 
the same branches of homologous veins." 
(2) Laws of Color-Patterns. As a result of my own study of 
the wings of moths and butterflies, I am prepared to propose the 
following additional laws of color-patterns. (a) Any spot found 
upon the wings of a moth or butterfly tends to be bilaterally symmet- 
rical both as regards form and color, the axis of symmetry being 
a line passing through the center of the interspace in which the 
spot is found, and parallel to the direction of the longitudinal 
nervures. For example, in Figs. 6 and 7, Plate 2, each spot is 
bilaterally symmetrical about the axis HH. The same law holds 
for the spots represented in Figs, 8-14 and 16. 
(b) Spots tend to appear not in one interspace only, but as a row 
occupying homologous places in successive interspaces. Indeed we 
almost always find similar spots arranged in linear series, each sim- 
ilar in shape and color to the others and occupying the center of its 
interspace, The rows of spots represented in Figs. 8-14 and 16 
will suflice to illustrate this law. 
It is interesting to notice that bands of color are often made by 
the fusion of a row of adjacent spots; and, conversely, chains of 
spots are often formed by the breaking up of bands, leaving 
a row of spots oceupying the interspaces. Many instances of this 
