MAYER: COLOR AND COLOR-PATTERNS. 185 
We see, then, that it is very common to find bands shrinking 
away from either end, but very rare to find them broken in the 
middle region. This, however, is only a special case of the law 
enunciated by Bateson (794), that the ends of a linera series are more 
variable than the middle. Almost any row of spots also exhibits 
the same law, in that the spots occupying the middle portions of 
the row are similar one to another, while those at the ends of the 
series depart more or less from the type. (See Figs. 10-13, 
Plate 2.) 
The position of spots which are situated near the edge of the 
wing is largely controlled by the wing-folds or creases. In Meli- 
naea egina (Fig. 96, Plate 8) there is a row of white spots near the 
outer edges of the wings, and each of these spots is cut in two by : 
narrow black line which extends along the wing-fold. Also in Cera- 
tinia vallonia (Fig. 81, Plate 7) and in many other forms of the 
Danaoid Heliconidae one often finds two creases in a cell, and in 
this case there are two marginal spots, one on each crease. In 
many other cases, however, the marginal spots are double in each 
cell, although there is but a single wing-fold ; the spots in these 
sases are situated at some distance on either side of the fold. (See 
Figs. 95, 96, Plate 8.) Another very common condition is exem- 
plified in Fig. 83, Plate 7, where there is a single marginal spot 
situated upon the wing-fold in each cell. 
(3) Detailed Discussion of the Laws of Color-Patterns. Pigs. 
6-14 and 16, Plate 2, are taken from special cases which serve 
to illustrate the two chief laws of color-pattern, 7. e., that spots tend 
to be bilaterally symmetrical about an axis (HH, Figs. 6, 7) passing 
through the center of the cell parallel with the nervures; and 
also, that spots of similar shape and color tend to be repeated in 
a row of adjacent cells. 
In Fig. 7 the spots are separated in the middle, but still incline 
outward symmetrically from the center; indeed, instances of double 
spots are very common. In such cases, however, each half spot is a 
refleetion of its mate on the other side of the axis passing through 
the center of the cell. 
Fig. 8 represents various eye-spots found in the Morphos, and 
will serve to illustrate the laws of eye-spots which have been enunci- 
ated by Seudder (89) and Bateson (94), These spots occupy the 
center of the cells in which they are found. In cell II, for example, 
is a large eye-spot with a crescent in. its center, and it will be 
