284 INTRODUCTION TO EMBRYOLOGY OF ANGIOSPERMS 



During further development, I gives rise to the cotyledons and stem 

 tip, V to the hypocotyl, h to the root tip, / and ci to the suspensor. 

 Saxifraga granulata (Soueges, 1936a) shows a variation in that 

 here the basal cell cb undergoes a few divisions to produce four to 

 eight large cells which form part of the suspensor. The terminal 

 cell ca first divides transversely to produce the two cells cc and cd 

 (Fig. 158 A), of which the latter divides into two daughter cells m 

 and ci (Fig. 1585). Of the resulting cells, ci divides vertically into 

 two juxtaposed cells which contribute to the middle portion of the 

 suspensor; and m divides transversely into/ and d (Fig. 15SD,E) 



ABC D E 



Fig. 158. Development of embryo in Saxifraga granulata. (After Soueges, 1936a.) 



the former contributing to the suspensor and the latter functioning 

 as the hypophysis. Meanwhile the cell cc undergoes two vertical 

 divisions (Fig. 158£,C) and one transverse division (Fig. 158D) to 

 give rise to the tiers I and V, which eventually produce the coty- 

 ledonary and hypocotyledonary portions of the embryo. 



The embryo of Androsaemum officinale (Soueges, 19366), belong- 

 ing to the family Hypericaceae, also deserves mention here. In 

 this case the terminal as well as the basal cell of the two-celled pro- 

 embryo divides transversely to give rise to a quartet of four super- 

 posed cells (Fig. 159 A, B). Of these the lowest cell cc divides 

 vertically into two juxtaposed cells (Fig. 159C), each of which under- 

 goes another vertical division to form the quadrant stage (Fig. 

 159D) and then a transverse division to give rise to the octants l-V 



