310 BOTANICAL GAZETTE [OCTOBER 
this it enlarges considerably on the side away from the raphe, and 
the sac becomes asymmetrical (fig. 55). This lateral growth 
continues until it extends even beyond the original position of the 
antipodal haustorium, with the result that the chalazal haustorium 
of endosperm origin comes to lie at the side of the sac rather 
than at its base, and the embryo sac extends below the chalaza 
(fig. 53). 
The embryo develops less quickly than does the endosperm. 
As stated earlier, the fertilized egg does not divide until after many 
free endosperm nuclei have been formed. The proembryo becomes 
differentiated into suspensor and embryo early in its development. 
By the time the embryo consists of several cells the suspensor, in a 
longitudinal section, shows but two cells. The cell adjoining the 
embryo is broader than long and the terminal one is but slightly 
longer than wide (fig. 49a). The suspensor, doubtless on account 
of the very effective micropylar haustorium, appears to be but a 
short-lived organ. It neither elongates nor becomes bladder-like, 
as is the case for many of the angiosperms, but soon breaks down 
and disappears. It shows signs of disintegration before the coty- 
ledons of the embryo appear (fig. 52), and by the time they are 
differentiated the suspensor has disappeared. The embryo de- 
velops at the tip of the suspensor and by the time the endosperm 
consists of two layers of cells about the periphery of the embryo 
sac the radicle and two cotyledons have become differentiated 
(figs. 53, 56). 
The embryo and the chalazal haustorium do not occur in the same 
vertical plane, therefore it is impossible to secure satisfactory sec- 
tions of the two from the same embryo sac. In the oldest stage 
studied a band of endosperm cells lines the sac (figs. 53, 56). The 
endosperm lies in close contact with the axis of the embryo and the 
sides of the cotyledons, but it is separated from the chalazal end 
of the embryo by a large cavity. Unfortunately, through lack 
of study of the seeds of J. Sultani, I was unable to determine the 
fate of the endosperm. According to GUIGNARD (22), a thin layer 
of endosperm remains undigested in the mature seed. BRUNOTTE 
(10), from his study of the Balsaminaceae, believes that the descrip- 
tions of the systematists for the mature seed should be changed. 
