364 Miyake— On the Development of the Sexual 
I have studied, cell-walls do not arise until after eight nuclei 
have been formed.’ 
Strasburger (’ 84 ^), describing the later process of proembryo- 
formation, states that the lower four of the eight cells divide, 
and the process is again repeated by the lowest four ; thus 
finally there are three tiers of four cells each, with four free 
nuclei above them h Coulter and Chamberlain (’01) give 
a similar description of the corresponding process in Pinus 
Laricio : ‘ The cells of the single completely walled tier then 
divide simultaneously, and two tiers are organized. The 
process is again repeated by the lower tier, and the result 
is three tiers of four cells each.’ 
The result of my observations is somewhat different from 
the above-mentioned process, which seems to be generally 
accepted. According to my observations, at first, the four 
nuclei of the upper incompletely walled cells divide simul- 
taneously, and another tier of completely walled cells is 
formed right above the lower tier (Fig. 58). Then the 
division is undertaken by the cells of the lowest tier and 
the formation of the proembryo is accomplished (Fig. 59) 2 . 
At this stage, therefore, there are four tiers of cells, of four 
cells each, the upper tier being incomplete since the nuclei are 
separated from one another by walls, but freely exposed above 
to the food supply of the egg. 
Abnormal Archegonia. 
Several abnormal archegonia have been observed in the 
course of the present investigations. The archegonium with- 
out a neck was often noticed (Figs. 60-61). This neckless 
archegonium has probably been originated from a cell below 
1 ‘ Die das Ende des Eies einnehmenden vier Zellkerne theilen sich in derselben 
Richtung weiter und die dem Ei-ende naheren wiederholen noch einmal die 
Theilung. So finden wir schliesslich in dem vom Halstheile abgekehrten Ende 
des Eies drei Etagen von je vier Zellen und liber diesen im Eikorper vier freie 
Zellkerne ’ (Strasburger ’84 b , p. 483). 
2 According to Miss Ferguson’s unpublished observation, which was kindly sub- 
mitted to”me, the process of proembryo formation of Pinus agrees with my result 
in Picea. 
