454 
Selective Elimhiation in Staphijlea 
produced by individuals rather than of the fitness of the individuals with given 
peculiarities. All will admit, I believe, that from the morphological and physio- 
logical view-point this problem is well worthy of careful study. In comparison 
with the results which may be obtained in quantitative investigation of selective 
elimination of individuals, the results should have real interest to students of 
evolution. 
A first study was made of the ovaries of the leguminous plant Gercis*. Here 
the results were negative, but there were certain limitations to the material which 
I have never succeeded in removing. The results were published for two reasons. 
First, I wanted if possible to interest others in a problem which needs the results 
of several independent researches for its solution. -Second, I had the present 
investigation nearly far enough along to see what the outcome would be, and 
I wanted to draw the conclusions from my first set of data quite independently 
and entirely unbiased by the evidence of a second study. 
II. Material. 
The fruit of the American Bladder Nut, Staphylea trifolia, is familiar to 
botanists as an inflated, membranaceous capsule of (generally) three locules, the 
dorsal sutures of which project to form three lobes. The carpels are (generally) 
united throughout the greater portion of the length of the fruit. From 4 to 
Fig. 1. Diagram showing the external appearance (A) and cross section (B) of fruit of Staphylea. 
Note the one seed and the arrangement of the aborted ovules in the front locule. The cross 
section of a young ovary (C) shows diagrammatically the disposition of the ovules of each locule in 
two rows along the inner angle. 
* Harris, J. Arthur: "Is there a Selective Eliminatioo in the Fruiting of the Leguminosae ? " 
Am. Nat. Vol. xlih. pp. 556—559, 1909. 
