322 BOTANICAL GAZETTE [ NOVEMBER 
“hypophysis,”’ whatever its origin, has fallen into much the 
same confusion as the terminal embryo cell. While the 
majority of text-books give its first division as transverse, fol- 
lowed by longitudinal divisions, the figures and texts disagree 
as to the subsequent development of its tissue. In Goebel’s 
Outlines, while the text describes the plate of cells, 2, of fig. 326, 
as dividing to form calyptrogen and root cap, in the figure 
itself 4%’ is divided instead of #. In Sach’s 7ext-book, h' is so 
figured and the text corresponds. 
It is unfortunate that such confusion exists in the embryol- 
ogy of Capsella, and however careful and accurate Hanstein’s 
original work may have been, he is either ambiguous in his 
statements or he has been mistranslated. It seems quite prob- 
able that Capsella is very close to Alyssum in its embryonic 
development and the many resemblances existing between some 
of the stages shown in my drawings and those of Hanstein seem 
to lead one to the conclusion that their embryology is very 
similar. Perhaps a re-investigation of Capsella would show its 
development to be the same. 
SUMMARY. 
1. The hypodermal archesporial cell divides into a tapetal 
cell and a macrospore mother cell which gives rise to four 
macrospores, three potential macrospores and a vital macrospore, 
the lowest of the series, which develops into the embryo sac. 
2. The embryo sac passes through the usual cell divisions, : 
increasing in size and becoming much curved, until the entire 
nucellus is destroyed. 
3. The antipodals are ephemeral, disappearing during the 
early stages of embryonic development. 
4. The endosperm appears soon after the fertilization of the 
oosphere. 
5. The first division of the proembryo is transverse and the 
basal suspensor cell never divides afterward. 
6. The end cell divides into the intermediate cell which 
contributes both to suspensor and embryo, and a terminal 
embryo cell. 
