J. W. Jenkinson 
155 
The results in the positive series agree fairly well with those obtained by the 
other method. The positive correlation between Plane of Symmetry and Sagittal 
Plane (p^y) and that between First Furrow and Sagittal Plane (pap) rise as gravity 
and pressure are successively removed, while the negative correlation between 
Plane of Symmetry and First Furrow (p^y) diminishes. 
Again, except when the eggs are close and their axes horizontal, the value of 
pay is greater than that of pap, the relation, that is, of the Sagittal Plane to the 
Plane of Symmetry is closer than to the First Furrow. 
In the negative series, where First Furrow and Sagittal Plane are on opposite 
sides of the Plane of Symmetry, there is a negative correlation between them, 
and this diminishes as the effects of pressure and gravity are removed : so also 
does the value of the negative correlation p^^- ^'^e third coefficient p^y (Plane of 
Symmetry and Sagittal Plane) is higher when both factors are removed than when 
both are present, but higher still when one is present and one absent. 
There are yet other ways in which the relative positions of the three planes 
may be compared. 
In Table XII. are given the equations to the regression lines, by which the 
mean values of any one of the three angles can be found when the value of one of 
the others is given. 
TABLE XII. 
Positive Series 
Negative Series 
Regression Lines ... 
a = 
/3 = 
7 = 
a= 
/3 = 
y= 
I. Eggs close. Axes 
liorizontal 
•2.51/3 + 26-97° 
■235 y +35-54° 
-.522n+ 16-2.5° 
- •765y + 35-54° 
-478a - 16-25° 
--749,3 + 20-97° 
--128^-26-01° 
-333y- 9-28° 
-•297a + 23^63° 
-•667y- 9-28° 
r297a- 
-1-128/3- 
23-63° 
26-01° 
II. Eggs close. Axes 
vertical 
-409,3 + 22-16° 
-500y +30-14° 
-410,1 + 13-42° 
--.500y + 30-14'^ 
-590a -13-42° 
--.591^ + 22-16° 
- -301/3-23-12° 
-.570y+ 0-14° 
--211a+ 16-55° 
--430y+ 0-14° 
1-211«- 
-1-301/3- 
16-55° 
23-12° 
in. Eggs spaced. 
Axes horizontal 
•413/3 + 21-60° 
-610y + 26-01° 
-31 2a + 13-12° 
--390y + 26-01° 
-688a -13-12° 
--.587/3 + 21-60° 
--281^-17-36° 
-.568y+ 1-17° 
--200a+ 14-85° 
--432y+ 1-17° 
l-200a- 
-1-281/3- 
14-85° 
17-36° 
IV. Eggsspaeed. Axes 
vertical 
-487/3 + 18-18° 
-680y +23-82° 
-309a + 12-68° 
- -3207 + 23-82° 
-691a -12-68° 
--513/3 + 18-18° 
- -0.52,3 -21 -.57° 
-5,50y+ 0-30° 
--042a+ 16-92° 
--450y+ 0-30° 
l-042a- 
-1-0.52/3- 
16-92° 
21-57° 
In the positive series the least mean value of a compatible with ^ being 
positive, 26"97°, is greater than the least mean value of /3 compatible with a being 
positive, 16"25°. In the negative series the least mean value of a compatible with 
/3 being positive is greater than the least mean value of /3 compatible with a being 
negative. 
All least mean values in the positive series dimitiish from I. to IV.: in the 
negative series they vary. 
20—2 
