108 MISSOURI BOTANICAL GARDEN. 
the seeds. In aloifolia, where there is no core and the 
fruits remain persistent until they dry up, it may be that 
the protection afforded the fruits by the reflexed leaves is of 
considerable importance. All indications here point to the 
fruit as being particularly modified for dissemination by 
small birds. The sweet tender pulp would be a tempting 
morsel for many animals, and not having a protecting core 
many of the seeds might be destroyed. 
The service which the reflexed leaves render in seed dis- 
semination has already been discussed. I would not con- 
sider, however, that this function has primarily had any 
influence in leading to the development of the habit of leaf 
reflexion. I am not disposed either to look upon the pro- 
tection which this habit affords the fruits of certain species 
as being the primary cause. Iam inclined to the opinion 
that the primary cause must. be sought for among the 
intricate relations between light and growth, coupled with 
the habit of growth of the plant, the reflexion being nec- 
essary to permit the accumulated seeds and rubbish caught 
by the erect leaves to fallto the ground. It may be merely 
the common habit shown by certain Monocotyledonous 
plants of this nature, such as palms which have tufted tops 
at the ends of tall trunks. The lower leaves of such trees 
gradually assume a reflexed position, evidently due to the 
pressure exerted by the development of other leaves above 
and an attempt to assume the most advantageous position 
in relation to the light. ‘The old leaves of palms gradually 
become strongly reflexed and ultimately dry up and break 
off, their bases frequently remaining attached for a time 
and then rotting away, leaving a smooth trunk. If this” 
habit were coupled with the development of phytomeroids 
such as occur in Y. aloifolia one might reasonably expect 
this leaf reflexion to become periodic, corresponding to the 
phytomeroids. 
The Clistoyuccas, having dry indehiscent fruits, include 
two species, gloriosa and brevifolia. Of the dissemination 
of gloriosa apparently nothing is known. While this plant 
