1918] DUDGEON—RUMEX CRISPUS 403 
any or all of the flowers of an inflorescence, and may or may not 
be accompanied by disorganization of the corresponding parts of the 
anthers. No instance has been observed of failure of all 6 anthers 
to start normal development, and nothing indicating disturbances’ 
in this development appears in the archesporial cell stage. It is 
very common, however, for the primary sporogenous cells to acquire 
small vacuoles (fig. 50), which merge into larger and larger vacuoles 
(fig. 51), until finally the cytoplasm is only a thin membrane lining 
the walls of the cell. It stains less and less intensely as the process 
goes on. The chromatin becomes aggregated into fewer and 
larger masses, which lie closely appressed to the nuclear membrane, 
and which stain very deeply. The nucleolus soon becomes indis- 
tinguishable. The nucleus becomes irregular in outline and 
shrinks, and in turn almost disappears. At the same time, the 
primary parietal cell, connective cells, and surrounding epidermis 
undergo a similar disorganization. Such a process usually is not 
confined to a single loculus, or even to a single anther, but includes 
all the stamens of a flower. Apparently if the degeneration process 
is not intense such cells may continue dividing for a time, forming 
anthers with all parts in normal relation (figs. 55, 56). Finally the 
cells become too weakened to divide further, and are nearly or 
quite empty. Anthers may be found in this condition that have 
developed almost to the mother cell stage. In the end, the arrested 
stamens break down and disappear completely before the flower 
opens. 
In other flowers the anthers may start normally, but individual 
cells in the sporogenous mass begin to degenerate, while the others, 
at least for a time, appear to continue normally (figs. 53, 54). Both 
cytoplasm and nucleus become more coarsely granular and very 
dense, and stain intensely. The protoplast pulls away from the 
cell walls, finally becoming only a shapeless dense mass in the 
central part of the cell. This process involves all the loculi of all 
the anthers of a flower, and may occur at any stage up to and 
including the mother cells. 
_ Normal microspore mother cells round off evenly and uniformly 
when the anther enlarges, and stain moderately. Mother cells in 
the process of degeneration round off into irregular masses, and 
