102 MISSOURI BOTANICAL GARDEN. 
active, the leaves beginning to dry up as soon as they 
become reflexed. In plants grown in rich soils or in 
well manured yards, the leaves of two or three phytom- 
eroids may frequently be found green and apparently 
active. 
While the reflexing of the leaves in Yucca alotfolia is 
probably not primarily to serve as an aid in seed dissemi- 
nation it is yet certain that it is of considerable service 
in this direction. The seeds which are dislodged by the 
mocking birds in feeding, as described above, being heavy 
fall into the crown of still erect leaves below, where they 
usually adhere to some one of the numerous leaves or slide 
down to the apex of the stem where the almost closed cup 
formed by the broad bases of the leaves effectually arrests 
and retains them until a later period of development when 
these leaves become reflexed. If on the contrary the falling 
seeds rattle through the cluster of erect leaves of the upper 
phytomeroid, on reaching the upper reflexed leaves of the 
lower phytomeroid which point downward and outward, 
they are shot outward by these, the force of the fall serving 
to throw them to a considerable distance from the parent 
plant. 
When the leaves of the upper phytomeroid, that bear- 
ing the fruit cluster, have become reflexed, the seeds 
which have been lodged in the cup formed by these before 
their reflexion, are gradually dislodged and are thrown out- 
ward by the reflexed leaves as they fall. Many may be 
dislodged by rain and washed downward but can hardly 
fail to be thrown outward as far as the ends of the leaves 
of the parent plant. Those seeds which fall when dry 
are frequently thrown outward to a considerable distance. 
The majority of them strike the ground from one to one 
and one-half meters distant from the base of the parent 
plant. This distance depends on the height of the plant 
and the angle to which the leaves are reflexed. I have 
examined some typical but exceptional cases, where the 
seeds could noticeably be seen to form a circle around the 
