402 BOTANICAL GAZETTE [NOVEMBER 
only the early stages have been investigated. As previously men- 
tioned, only a relatively small number of flowers ever proceed to 
fruit formation. The embryo and endosperm are of the well known 
Capsella type; the suspensor may become about ro cells long, and 
occasionally some of the cells divide longitudinally. All parts of 
the ovule elongate greatly, and the integuments and walls of the 
nucellus finally become compacted into a single thin layer. The 
carpels become much thickened and the cells strongly lignified. 
The petals enlarge and elongate to keep pace with the developing 
fruit, and function as protective organs (valves), while the tissue 
on the abaxial side of the midrib of each proliferates and forms the 
characteristic tubercles. The sepals alone, of all the structures in 
the maturing flower, fail to enlarge, and remain tiny flaps at the 
bases of the petals. 
Degenerations 
It soon became apparent that the most striking and significant 
feature in the flowers of Rumex crispus is the wholesale degenera- 
tions that occur. These degenerations may go on in either the 
stamens or the carpels, or in both at the same time. They are 
characterized in some cases by lighter staining and increasing 
vacuolation of the cytoplasm, until it becomes an almost indis- 
tinguishably thin peripheral layer, and the aggregation of the chro- 
matin into fewer and larger masses, with irregular outline of and 
final collapse and disintegration of the nucleus. Such changes are 
characteristic in the earlier stages of development of the stamens. 
In other cases, the cytoplasm increases in density and staining 
power, and plasmolyzes away from the walls; the nucleus becomes 
deeply and uniformly granular, and finally stains as a solid homo- 
geneous mass; the protoplast ultimately shrinks into a blob in 
which no trace of the original structure can be distinguished. 
DEGENERATIONS IN THE STAMENS.—Degenerations. in the 
stamens may begin at any stage, from the primary sporogenous 
cell to the pollen grain, and may involve part or all of the sporoge- 
nous tissue, part or all of the microspore mother cells, one to all 
of the spores of a tetrad, any or all of the microspores, and any or 
all of the pollen grains, in any or all of the loculi of the anthers, in 
