space within the testa. The final shape is prepared for very early 
by two processes. The one is a curvation of the ovule (see 
Fig. 1. Salsola Kali; c, embryo sac; a, b, d, ovary cavity with ovule, respecti- 
vely on embryo sac mother cell, 8-nuclear embryo sac, and 2-cell-embryo stage (a 
and c X 440, b x300, d x130; the straight lines stand each for 0,1 mm). 
figure a, b, and HEGELMAIER'S, pl. IV, fig. 10), the other is a bending 
over of the curved ovule so that its median plane, at first longitu- 
dinal to the ovary, becomes finally transversal. As to the causes 
of these processes, it is at first to be remarked that the section 
