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THE PLANT WORLD. 
open (Fig. 27, E). A slight ridge on the inner edge of each 
margin of the carpel prevents for a time the escape of the twisting 
endocarp. The placenta separates, forming another, thin trough¬ 
like piece (Fig. 27, C), the margins of which are inside of the 
endocarp. The two seeds separate from the placenta which sets 
loosely over the seeds, preventing them from falling out in case 
the branch bends down toward the ground. Seeds are torn off 
Fig. 27. Entire pistil of Dictamnus albus. a, carpel closed; b, carpel 
beginning to open; c, thin placenta freed from rest of carpel and seeds; 
d, two seeds partially covered by placenta; e, margins of free endocarp, 
spreading exocarp open; f, extremities of one-half endocarp. 
the placenta as this dries, shrinking away in the central portion 
and lastly at the ends, which approach each other slightly. 
Each half-endocarp resembles in a general way a capital letter 
J (Fig. 27, E). The apical portion of the endocarp presses out¬ 
ward, while the basal portion tends to twist inward. When dry 
enough, and the carpel spread open well, if the stems are jarred 
