404 BOTANICAL GAZETTE [NOVEMBER 
stain more or less intensely according to the degree of disorganiza- 
tion. These cells are capable of passing through the reduction 
divisions (fig. 61), and chromosome number, spindles, and the 
tetrads formed appear to be normal in essential features, but they 
stain very deeply and the outlines are irregular. 
Usually if the anther walls have developed unimpaired to the 
reduction stage, they can reach maturity and produce a normal 
appearing organ. Many, however, begin to collapse, and it is very 
common to find examples in which the walls have collapsed closely 
against the sporogenous tissue within, while the cells and walls are 
much wrinkled and distorted (fig. 61). Earlier degenerations are 
likely to include all the stamens of a flower; later degenerations 
may include only one or two loculi of one anther, or only one or a 
few of the 6 anthers (figs. 11, 12). In one case in particular, one 
of the loculi of an anther had degenerated early and left only a 
small deeply staining spot at the side of an otherwise normal organ 
(fig. 12a). 
As already mentioned, the tapetum is involved along with the 
other parts. A few anthers have been observed in which the 
sporogenous cells had degenerated completely into dense shapeless 
masses, while the walls and tapetum had remained relatively 
unaffected; the wall cells were thicker than normal, and the tapetal 
cells had become much larger and projected like papillae against 
the contracted, disorganized, sporogenous tissue (fig. 59) 
By the time reduction is completed, the tendency to degenera- 
tion has become so universal that only a few microspores appear 
normal. It is not uncommon to find even the spores of a tetrad 
in widely different stages of disorganization; one or two will 
appear almost normal, while the others are mere masses of stain 
(fig. 62). In such cases it is certain that spores that do not stain 
so intensely are really affected. Spores that survive liberation 
from the tetrad may shrivel up, with the cytoplasm more and more 
closely packed about the diminishing nucleus, until finally nothing 
is left but the wall with a little mass collapsed against one side (figs. 
63, 65, 66). 
Very many spores proceed to wall formation and the usual 
divisions to complete the male gametophyte. Only in a few 
