160 BOTANICAL GAZETTE [FEBRUARY 
masses of sister leaves produce equal masses of shoots in equal time, 
even if the number of shoots in the two cases is in the ratio of 1:2. 
In order to test further this law it seemed necessary to modify 
the experiment. For this purpose the mass of one of two sister 
leaves was reduced by cutting out a large piece from the center, 
leaving the edge intact (fig. 8), while the other leaf remained 
intact (fig. 7). If the law just expressed is correct, it should follow 
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Fic. 7 Fie. 8 
Fics. 7, 8.—Sister leaves suspended in moist air: fig. 7, leaf intact; fig. 8, leaf 
with mass reduced by cutting out large piece from center of leaf; mass of shoots 
produced smaller than that produced by intact leaf; drawn 23 days after beginning of 
experiment. 
that the mass of shoots produced by such sister leaves (one set of 
which remained intact while the mass of the other set was reduced 
by cutting out pieces from the middle) would no longer be equal, 
but would differ in proportion to the mass of the two sets of leaves. 
This was found to be approximately true, as table VIII indicates. 
Thus in experiment I (table VIII) the 5 intact leaves weighing 
13.8 gm. produced in 37 days 1405 mgm. of shoots, while their 5 
