1918] DUDGEON—RUMEX CRISPUS 409 
even the cells of the ovular vascular bundle (figs. 13, 14, 20). This 
bundle flares out against the lower side of the impervious chalazal 
plate (fig. 13), and there is no passage of normal cells anywhere 
connecting it with the nucellus. The lower end of the bundle 
terminates blindly in a patch of permanently thin-walled paren- 
chyma, with absolutely no connection with the vascular system 
traversing the peduncle and branching to supply the other parts 
of the flower (figs. 19-21). Below this parenchyma, between 
the traces to the sepals and petals, and removed by 8-10 paren- 
chyma cells from the end of the ovular bundle, the bundle of the 
peduncle terminates in a broad axial mass of short tracheids. One 
thinks of the patch of parenchyma as a reservoir, filled from the 
bottom by the bundles of the peduncle, and emptied by an ovular 
bundle dipping into the top. 
DEGENERATIONS IN ENTIRE INFLORESCENCE.—Degenerations 
are not always confined to scattered flowers, but may involve all 
the flowers, especially the terminal portions of large or late inflores- 
cences. The earlier in the development of the inflorescence that 
the degeneration processes set in, the larger is the number of 
flowers involved. 
ABSCISSIONS.—Accompanying these degenerations is a strong 
tendency for parts to absciss. There is a definite abscission layer 
formed near the base of the peduncle (fig. 16), which leads to 
dropping off of those flowers in which extreme early degenerations 
have appeared. A ring of epidermis remains thin, and the under- 
lying cortical cells remain meristematic. The exact method of 
operation has not been followed; it is probable that the mechanism 
is called into activity by the same causes that result in failure of the 
other floral parts. 
The fully developed filament of the stamen is a short thick stalk, 
traversed by a small vascular-bundle. All the mature stamens 
that were observed were either entirely separated from the flower, 
or at least physiologically separated, by disorganization of the 
upper end of the filaments. The epidermis and cortical cells 
break down, leaving the anther attached by the vascular bundle 
only (fig. 19a). Soon this is severed also, and the anther is held in 
the flower only by the floral envelop, to be dropped out upon 
