LIMITS OF HEREDITARY CONTROL 871 
given in convenient form the data, band for band. The arrays 
for the individual bands are considerably more satisfactory for 
purposes of seriation than that for the banded region as a whole; 
for the number of classes is comparatively small and consequently 
the number of counts sufficient to give a smooth curve without 
any grouping of variates. As a sample of the type of curve 
derived from a seriation of the variates of the individual bands 
let us take that of band 1 (fig. 2). 
100 
Sy) 55) 57 58 59 60 61 62 63 64 65 66 67 68 69 70 7h: 
Fig. 2 Polygon of variation for the total number of scutes in the first band, 
as determined from a seriation of 508 individuals. Class range = 8 scutes. The 
solid line represents the observational and the broken line the theoretical normal 
curve. 
It will be noted that the mean, mode and median coincide and 
that the observed and the calculated curve are almost identical. 
The curves for the other bands are of the same type as that shown 
for band 1. These observations would seem to indicate clearly 
enough that in the distribution of the elements of the integument 
into bands we have a pure chance process controlled by fairly 
simple mechanical laws. 
JOURNAL OF MORPHOLOGY, VOL. 22, No. 4 
