EARLY DEVELOPMENT OF CAPSELLA 



49 



the suspensor, and serves for the attachment and nutrition of the 

 embryo, which at first develops entirely at the expense of the 

 parent, having no means of feeding itself. All the cell-divisions 



-b.c. 



FIG. 14. Four stages in the early Development of a Flowering Plant, 

 Capsella bursa-pastoris, X 200. (From Scott's " Structural Botany," 

 after Hanstein.) 



b.c., basal cell of suspensor; ct., cotyledons growing out ; d, dermatogen ; e, embryonic 

 group of cells; ff.p., growing point of stem; h, uppermost cell of suspensor; 

 pe, penblem ; pr, pi, cells of plerome; j s cells derived from h. 



so far have taken place in planes parallel to one another, thus 

 giving rise to a single row of cells, but the embryonic cell now 

 divides into four parts by the formation of two cell-walls at right 

 angles to each other and to the preceding divisions (Fig. 14, 

 A, e), and each of these again divides into two by the formation 



