448 BOTANICAL GAZETTE [DECEMBER 
departure from the type is the lack of the cross wall that cuts off a 
uninucleate cell at the tip of the hypha.’”’ Later on he says that in 
some of the species the cross wall may be exceptionally present. 
In this statement he probably includes L. chlorocephala, as the cross 
wall is frequently present in this species. L. chlorocephala, how- 
ever, shows quite a number of other deviations from what has 
been regarded as the usual type. 
The tips of the ascogenous hyphae in the hymenium usually 
contain two nuclei, and become shaped like a hook (figs. 21, 22). 
The nuclei then divide, giving rise to four nuclei (fig. 23). Walls 
may then come in between the sister nuclei (fig. 24), or the wall 
cutting off the terminal cell may not be developed (fig. 25), or 
in still other cases both walls may be lacking even after the two 
nuclei in the bent portion of the hook have fused to form the nucleus 
of an ascus (fig. 26). When the nuclei are distributed as in figs. 
23, 24, so that one is in the tip and two in the bent part of the hook, 
the two nuclei (apparently not sisters) in the bent portion may 
fuse to form the nucleus of an ascus (figs. 26, 28a), or they may — 
give rise to the four nuclei of another hook (fig. 29). The uninu- 
cleate tip usually grows down and fuses with the stalk of the hook 
(fig. 26). The nucleus of the stalk may then migrate out into the 
tip (fig. 27), which usually grows out to form another hook (fig. 28), 
or sometimes an ascus (fig. 30). That in these cases it is the tip 
which has developed below the ascus is shown by the presence of 
the curved end of the tip joined to the stalk cell, as well as by the 
presence of both the wall which separated the ultimate cell from 
the penultimate and the one which divided the penultimate from 
the antepenultimate. The nucleus from the tip of a hook may 
occasionally migrate into the stalk. Sometimes the nucleus 
formed by the fusion of the nuclei of the tip and stalk does not 
develop further (fig. 29). This is usually associated with a vacuo- 
lated condition of the cytoplasm which indicates that the failure 
of the tip to develop is due to a lack of food. The processes 
described above, by which either the tip or bent portion of a hook 
may form another hook, are apparently often repeated many 
times, so that even in a young stage of the hymenium five or six 
hooks are frequently seen joined together in various = This 
is shown diagrammatically in fig. 31. 
