160 Symmetry of Egy and Symmetry of Embryo in the Frog 
Fig. 10. Eegression Scbenie constructed from Table VIII. The dots are the means of the angles 
between Plane of Symmetry and Sagittal Plane for each class of angle between First Furrow 
and Sagittal Plane. 
TABLE IX. 
Constructed from the Central Squares of Table VIII. 
45 Totals 
First Furrow and Sagittal Plane. 
+ 
c 
4 
2 
1 
2 
3 
12 
6 
8 
8 
4 
2 
4 
32 
5 
9 
26 
10 
6 
3 
59 
4 
2 
9 
26 
9 
5 
55 
2 
4 
5 
2 
20 
5 
38 
2 
3 
5 
4 
5 
19 
45 
Totals 23 
26 
I 50 I 48 I 
p=-27] ±-038. 
43 
25 
215 
The examination, therefore, of a fairly large number of instances 
(1) supports the statement that the first furrow and the sagittal plane tend 
to coincide, though deviations of any magnitude are possible ; 
(2) but contradicts the supposition that there is any causal nexus between 
the two ; 
(3) shows that the symmetry of the egg has a marked effect upon the 
symmetry of the embryo and upon the symmetry of segmentation. The effect, 
however, is not the same in the two cases. 
