1897 | STAMENS AND CARPELS OF TYPHA LATIFOLIA 97 
toward the funiculus. The ovule receives a fibrovascular bundle 
which, as it leaves the funiculus, passes down through the wall of 
the carpel (fig. g8) and unites below with the bundle which 
passes up on the other side into the leaf-like stigma. From this 
it appears that the ovule is an axillary structure developing at the 
end of a fibrovascular bundle which represents a branch of the 
main bundle of the carpel. 
DEVELOPMENT OF THE MACROSPORE AND FEMALE GAMETOPHYTE. 
In the young nucellus there can be distinguished, at a very 
early stage, a hypodermal cell which is somewhat larger than 
the surrounding nucellar cells (fig. 33). This, as its subsequent 
history shows, is the archesporial cell. This cell divides and cuts 
off one primary tapetal cell (fig. 75), and subsequently the pri- 
mary tapetal cell divides by a vertical wall, forming a tapetum 
of two cells (figs. 37-gr). In the rear of the primary sporo- 
genous cell, or the macrospore mother cell, a long axial row of 
cells is developed (figs. 38-gr). Often, if the section is not 
quite longitudinal, so that only three or four of the cells of the 
axial row are left back of the macrospore mother cell, there is 
an appearance as though there were a row of four or five macro- 
Spores. It is evident that extreme care must be taken not to 
mistake the large cells of the axial row for potential macro- 
Spores. It is possible that misinterpretations may sometimes 
have been made in this way. In Typha I was only able to 
determine conclusively the real fate of the macrospore mother 
cell by tracing out its development step by step, so closely did 
the cells of the axia! row agree in size, structure, and staining 
reaction with the macrospore mother cell. The macrospore 
mother cell develops directly into the fertile macrospore without 
any division, and soon after the integuments have made their 
appearance it begins to encroach upon the tapetal cells which 
are destroyed in a short time (figs. 41-43). 
It is surprising that Typha, which represents such a primitive 
condition in the organography of its flowers, should represent 
what must be regarded as a highly modified archesporial region 
