1915] AYRES—FLOWER OF ADENOCAULON 155 
whorl of five strands about a central strand. The latter terminates 
at the base of the sterile ovarian cavity; while the five strands 
about it pass up about the ovarian cavity until they reach half 
of its length (fig. 13, b*). Then the two of these strands which are 
opposite to the two lobes of the stigma branch (fig. 13, 6), each 
branch passing up into a lobe of the stigma. The main branch of 
each of these two strands and also the three other main strands 
pass up into the corolla, where each branches just below the base of 
its opposite stamen (fig. 13, 03); one branch passes up into the 
stamen, and the main one continues up into the apex of the corolla. 
The fact that the stigma is cleft does not agree with descriptions 
in ENGLER and PrAntw’s Die natiirlichen Pflanzenfamilien, Brit- 
TON and Brown’s Iilustrated flora, and HowE.t’s Flora of North- 
west America. 
In the pistillate flower the history is the same up to the develop- 
ment of the ovarian cavity. When the base of this cavity broadens 
(fig. 12, 7*, oc), a bulge appears, which is the beginning of the ovule. 
The megaspore mother cell is formed in-the usual way, and 
occupies all or nearly all of the outer end of the nucellus. Behind 
the megaspore there is crowded a row of two or three other rather 
large cells, which gives the appearance of a row of three or four 
megaspores. Sometimes other cells remain at the side of the 
mother cell, and the outermost ones are often elongated and 
resemble the mother cell in size but not in content (fig. 14, m1). 
The megaspore mother cell passes through the usual two successive 
divisions, and the inner megaspore becomes the embryo sac (fig. 21). 
The embryo goes through the same phases of cleavage (fig. 22) 
as those reported by MERRELL' in Silphium. 
When the megaspore mother cell has enlarged (fig. 14), the first 
gland-hairs appear on the akene. Usually the first glands appear 
just where one would expect a calyx. This leads one to suspect 
that the tendency of the cells at that point to form projections is 
still slightly more marked than at other points. These glands 
develop from a protrusion of four epidermal cells of the akene. 
These cells are large and have large nuclei (fig. 15). They elongate 
and form a knob on the end (figs. 15-19). Many more glands 
* Bor, Gaz, 29:115-124. 1900. 
