I2 : BOTANICAL GAZETTE [JULY 
Fig. 48 shows the formation of what is probably in the majority 
of cases a last initial cut from the base of the cover cell. Abun- 
dant evidence has been found that at some time between the 12-16 
neck canal cell stage the cover cell changes its manner of division 
and segments by a wall perpendicular to its base into two more or 
less equal parts (figs. 50, 51, 54, 56). The division figure was 
found once and is shown in fig. 56. No evidence could be obtained 
that the division may occur before the 12 neck canal cell stage; while 
after the 16 neck canal cell stage practically all covers showed 
division. Out of the large number of cases studied only two excep- 
tions were found, one a case of 18 neck canal cells, and the other a 
case of 20 with the cover in each yet undivided. Such a process, 
then, while occurring within general limits is by no means fixed. 
Whenever such a division does occur, it signalizes the end of 
all true apical activity. The segmented cover stands out well 
defined from the peripheral segments of the neck and its history 
can be followed for some time with a reasonable degree of accuracy. 
Thus in figs. 61 and 62 the cover cell has formed 6 segments 
(3 shown in median longitudinal section) and is literally the cap of 
the archegonium. In fig. 72A we have the cross-section of the 
_ cover of an archegonium containing 35 neck canal cells. It shows 
7 clearly the primary: division es I-I}; the Lowap walls 2-2; and 
th d When the archegonium 
is fully matured the sepments oF the cover merge insensibly with 
those of the neck, hence an exact statement cannot be made as to 
the final number produced. | : 
o The division of the ventral cell into ventral canal cell and egg 
ae found five times, 3 being shown (figs. 47, 50, 53). Here again 
: ‘ one finds the same sort of variability noted for the cover cell, but — 
- with a slightly greater range. The division may occur as early 
as the rz neck canal cell stage (fig. 47), while several cases were __ 
found in which there were 17-20 neck canal cells sath the Yentet yet : 
ae / : undivided (figs. 58, 60). The ventral canal = 
_ division is quite variable in size. Sometimes it is about the : shine 
se ‘size as the egg (figs. 56, 6, 68); or it aay. ae Botiecably smaller 
G54, 3,68). 
_Asalready stated, the cutting off of initials from the base of the s 
| one elem se eaneey of cases brought to a cx : : 
