382 PEIRCE: ForcIBLE DISCHARGE OF ANTHEROZOIDS 
of the antheridium and the discharge of its contents through the 
"mouth of the chamber, the total force expanding itself all in one 
direction with the astonishing result just described. 
The distance to which antherozoids will be thrown will depend 
on the one hand upon the turgidity of the antheridia and of the 
vegetative parts of the plant, and on the other hand upon the posi- 
tion of the plant and upon the wind. The antherozoids may be 
thrown violently against nearby objects, leaves, branches, etc., 
when the force was sufficient to have carried them much farther if 
the plants had only been growing in more open places. But the 
main external influences are wind and water. The wind may 
blow the antherozoids back upon the parent plant or take them 
far away, dropping them near female plants or scattering them 
where there are none. When the antherozoids fall to the ground 
they must swim the rest of the way if they are to accomplish their 
purpose. An enormous number of antherozoids are discharged 
from each antheridium, and there are several or many antheridia on 
each male plant. Without counting at all, I should say that there 
appear to be about equal numbers of male and female plants, and 
that the number of archegonia is about the same as the number 
of antheridia. At all events the number of antherozoids enor- 
mously exceeds the number of egg-cells. Since these plants are 
dioecious, cross fertilization is all that is possible. But what does 
the plant pay for this? The dioecism of this species is coupled 
with the forcible discharge of the male elements. These may oF 
may not be transported by this means nearer to the female ele- 
ments which they must reach by swimming and with which they 
must fuse if they are to be useful. 
It would be interesting to know whether other dioecious liver- 
worts have this same habit. I hope next year to test other plants 
for this phenomenon, but I do not wish by this statement to 
reserve the field to myself. 
PHYSIOLOGICAL LABORATORY, 
LELAND STANFORD Junror University, 
January 31, 1902. 
