64 SPERMATOGENESIS AND FECUNDATION OF ZAMIA. 
the pollen tube be touched very lightly with the flat side of a scalpel 
it bursts, and the spermatozoids, together with a drop of the watery 
contents of the pollen tube, are quickly forced out and the pollen tube 
immediately shrivels up into a shapeless mass. This the writer thinks 
is what happens in the normal course of fecundation. The pollen 
tube evidently grows down until the end is forced against the neck 
cells, when the tube bursts, discharging the mature spermatozoids and 
the watery contents of the tube, which supplies a drop of fluid in which 
the spermatozoids can swim. Some doubt exists as to whether the 
pollen tube supplies all of the fluid in the archegonial chamber at the 
time of fecundation or whether some of it is extruded by the egg cell. 
Hirase (62, p. 122) described the occurrence of a sap filling the 
archegonial chamber at the time of fecundation, and considered that 
it was very probably a product of the female organ. No evidence is 
given, however, to show that this is the case. Ikeno (70, p. 583) also 
thinks that the fluid is largely a product of the female organ. He 
Says: 
I have often met with cases in Cycas in which fluid was already present, in spite of the 
fact that all pollen tubes were yet entirely intact; so that we are led to the conclusion 
that at least a part of this fluid—probably the larger part—proceeds from the female 
organ.! , 
If Ikeno was not mistaken in his observation, he is certainly correct 
in claiming that the female organ furnishes part of the fluid. In 
Lamia, however, the writer has frequently observed that the numer- 
ous pollen tubes are in various stages of development. One tube may 
have the spermatozoids swimming about in it, while in an adjoining 
tube the central cell has not yet completed its division. When a tube 
has burst and dicharged its spermatozoids it shrivels into an unrecogniz- 
able, small, and almost indiscernible mass. Tubes in an advanced stage 
may burst and leave a liquid in the archegonial chamber, while other 
tubes remain entire. In Zama a portion of the fluid is certainly fur- 
nished by the pollen tube. Whether any of it is furnished by the 
female apparatus the writer has been unable to positively determine. 
It may be so, but the neck cells remain turgid and fresh up to the very 
time of fecundation, and no indication of the beginning of the exuda- 
tion of a fluid has been observed, though it would seem that an abun- 
dant opportunity has been furnished for observing such an exudation 
if it occurs. ; 
The writer has several times observed the spermatozoids after they 
were discharged over the archegonia, but studying them in this posi- 
tion is unsatisfactory and difficult. They have been observed to swim 
lIch habe bei Cycas oft Falle angetroffen, in denen eine Menge Saft schon in der 
Endospermhohle vorhanden war, wenn auch alle Pollenschliuche noch ganz intact 
waren, so dass wir zu der Annahme geftihrt werden, dass wenigstens ein Theil dieses 
Saftes—wahrscheinlich der grosste Theil—aus dem weiblichen Organe herstammt. 
