W. Rowan, K. M. Parker and J. Bell 
lol 
feature we have already indicated as difficult to measure It will be seen that 
the coiTclation of the ground colour of an egg with the mottling of a second 
(■■3989) has come out greater than the organic correlation between mottling and 
ground colour in the same egg (■2260). 
TABLE IV. 
H uinnti/pic Currelations. 
Symbols 
Characters 
Correlation 

L, L 
B, B 
Gi, Gi 
Gf,, Gf, 
Length!^ of Eggs in same elutch ... 
Breadtlis of Eggs in same clutch ... 
Longitudinal (iirtlis of Eggs in same clutch 
Equatorial Girths of Eggs in sanie clutch 
■4643+ ■0346 
■5176+ ■0326 
■5076 + ^0327 
■4621 ± ^0350 
Direct 
Mean value 
■4879 
M, M 
6, 6 
Mottling of Eggs in same clutch ... 
Ground colour oi Eggs in same clutch ... 
■3500 
■5709 
Mean of six characters ... 
■4788 
Cross 
Z, B 
C, M 
L, G, 
B, 
Gi, G,, 
Length of one Egg with Breadth of a second ... 
(xround colour of one Egg with Mottling of a second 
Length of one Egg with Longitudinal Girth of a second 
Breadth of one Egg with Longitudinal Girth of a second 
Longitudinal Girth of one Egg with Equatorial Girth of a second 
■0922 + ^0441 
•3989+ ^0379 
■4229 ± ■0362 
•2530+ ^04 16 
■2603± ^0413 
Index 
B/L, B/L 
0, 0 
//O, IjO 
Indices of two Eggs of same clutch ... ... 
Indices of ovality of two Eggs of same chiteh ... 
Inverse of indices of ovality 
•5537 ± ^0308 
•5527 + -0309 
■5361± ^0317 
Mean of three Index Correlations 
Mean of nine Homotypic Coi'relations 
■5475 
■5017 
We feel that the classification by mottling is at present too uncertain, and 
that until the result cited has been coniirmed with larger numbers and more 
definite categories, it would be idle to consider whether, while a given bird has 
usually highly or lowly pigmented eggs both as to ground colour and mottling, 
yet when in the individual egg there is an excess of mottling pigment, there 
may be some tendency to a relatively less increase of ground colour. Thus the 
correlation in the individual egg might possibly be less than the correlation 
between eggs of the same clutch. Such considerations must be postponed until 
the fact itself is adequately demonstrated. 
