1918] LOEB—CORRELATION 157 
the number of shoots in the two leaves may differ. The variations in 
the results lie within the limits of the unavoidable errors of the 
experiments. 
TABLE IV 
INTACT SISTER LEAVES; MARCH 20—APRIL 18, 1917 
s : Mem. of shoots 
. Number of | Weight of shoots| Weight of | 
Sister leaves cist lig ba poly se ed . re ea ae —-. 
I bese Less aa 3 0.127 1.370 07 
POARORT Bi Scoaieeoves Co 2 0.128 I.170 109 
ll ON eee ae aan 2 0.150 1.595 
LAME Fie ee ee 3 0.1325 4.333 100 
III TEARS ©2556 55: 4 0.2085 I.Q175 109 
RRMA Foes 05 Oy a 0.1575 1.722 oI 
TAME Ese vere 3 0.270 2.286 118 
IV. {eal See 4° 0.145 1.586 gI 
V pe By pc sauaws ici’ 2 0.147 1.3385 110 
: Fee SEE 5 0.2075 2.061 Iol 
SAE ES 4 0.211 I.9735 107 
VI. pee Roe ak ee Wes 3 0.220 2.0275 107.5 
BORE Pe: 2 ©. 1065 0.90435 113 
vit. Teet Pe Rag ES 3 0.105 1.062 99 
PEM Be ie bwcks sy 5 0.233 2.332 100 
. VEL. (reat Ree ee 4 0.228 2.2595 IOI 
ee on eae 1.452 13.69 106 
Average oti need COS a tel Naas 1.322 13.21 100 
It would follow that if we cut a leaf into two symmetrical halves 
each half should produce equal masses of shoots in the same time 
and under the same conditions. This is approximately correct, as 
table VI shows. 
The experiment was ceil (table V), and we may confine 
ourselves to a statement of the average result. The two halves are 
designated as right and left, when facing the observer with their 
basal end and when lying on their lower side. 
It is obvious, therefore, that if leaves are cut symmetrically, the 
two halves will produce in equal times and under equal conditions 
on the average exactly the same mass of shoots, even when the 
number of shoots in the two halves varies. 
