ite. BOTANICAL GAZETTE [MARCH 
FiG. 50. S. petiolaris. Quadrant stage; second division of embryo longi- 
tudinal. 
FIGs. 51, 52. Quadrant stages in S. fetiolaris and S. cordata respectively. 
FIG. 53. S. acaalen: Octant stage; upper cell of suspensor has given 
rise to a plate of four cells; synergid persisting. 
Fic. 54. S. petiolaris. Quadrant stage: embryo small as oe with 
the suspensor. 
FiG. 55. S. fetiolaris. Irregular embryo. 
Fic. 56. S. cordata. Dermatogen cut off in one segment while a neigh- 
boring segment is developing farther before cutting off dermatogen. 
Fig. 57. S. fetiolaris. Lower cell of suspensor much enlarged. 
Fig. 58. S.cordata. Irregular embryo. 
FIG. 59. Ss. petiolaris. Embryo of sport; variation in the stage at which 
F1G. 60. S. cordata. Early division in middle cell of suspensor. 
Fic. 61. S. fetiolaris, Three-sided apical cell. 
Fic. 62. S. cordata. Apical cell. 
F1G. 63. S. cordata. Later am of embryo which started to develop by 
an apes cell. 
r1IG. 64. Surface view of same embryo as fig. 63. 
Fic. 65. S. glaucophylla. All dermatogen cut off except the suspensor 
contribution; sixteen cells inthe embryo besides the dermatogen. 
PLATE XFVEH. ¢ 
Fic. 66. S. fristis. Root end of nearly mature embryo, showing character 
of various cells; periblem and plerome not entirely differentiated at the apex. 
Fic. 66a. Outline sketch of same embryo showing cotyledons and apex 
of stem. 
FiG. 67. S. ¢ristis. Peribl nd plerome diff d even at the apex; 
initial cell of plerome and one scieuneint more deeply shaded; dermatogen 
and four layers of root cap also shown 
Fic. 68. S. glaucophylla. pone before differentiation of the dermato- — 
tip. 
gen of the root 
Fic. 69. S. ¢ristis. Transverse section of embryo in the stage oueie te a 
Ag. 66, taken a few cells above the common meristem of periblem and 
plerome. 
Fig. 70. Ss. plmceeiyh Za. Embryo unusually symmetrical in its divisions. 
Fic. 71. S. glaucophylla. Very a embryo showing the zone of 
cells (z) just below the first transverse wall 
Fig. 72. S. tristis. Dermatogen of 1 root tip differentiated ; ‘no trace of a 
separation into 
“Fi aan S. glaucophylla. “Embryo. showing zone of cells. @s develop: p- 
aie: ee 
