18 BOTANICAL GAZETTE [JULY 
the division of the generative cell (figs. 2 and 5 A). The Haut- 
schicht of the cell is bent in where the band is located, forming 
a deep spiral groove. By this the band is brought to the sur- 
face of the cell, but apparently remains covered by the Haut- 
schicht through which the cilia appear to penetrate 
\, (jigs. 2 and 3). 
yy While the generative cell and the anthero- 
zoids are developing as above described, the 
proximal ends of the pollen tubes, which, as 
noted in my previous paper,3 grow downward 
through the apical tissue of the nucellus into 
- Cross 
section ot spiral a cavity formed in the prothallium above the 
band, showing at- archegonia, have increased in length until the 
tachment of cilia - 
< Ode: ends almost or quite touch the neck cells of 
the archegonia, which protrude into the same 
cavity. It is interesting to note that the pollen tubes when 
they enter the prothallium cavity, which is filled with air, do not 
grow at random, but bend slightly outward and grow directly 
toward the archegonia. Frequently several turn toward the 
same archegonium. The end of the pollen tube is occupied 
by the proximal cell, described in my previous paper, which 
remains intact till the pollen tube bursts in the act of fecunda- 
tion. The antherozoid cells at this stage 
invariably occupy a position in the pollen 
tube immediately above the proximal cell (jig. 
5A). The end of the tube is wider than the 
upper portion and is evidently under consider- 
able tension. The protruding tip formed by 
the old pollen grain ( fig. 5 pg) is plainly visible 
with a hand lens, and is evidently the point ro eee 
which first comes in contact with the neck siuupeerainalt akasg's 
cells of the archegonia. - The neck cells are also distended and 
turgid, and are evidently easily broken. If in this stage the end 
of a pollen tube be touched very lightly with the flat side of a 
scalpel it bursts, and the antherozoids together with a drop of 
3 Of. cit., 455, Fl. XL, fig. 6. ~ ; 
