FERTILISATION OF RED SEA-WEEDS BY ANIMALCULE. 399 
signification to that of the elongated style in many phanerogams, 
while the central part (cg) of the carpogonium is the anologue 
of the closed ovarium of angiosperms... The trichogynium is a 
tender, colourless hair consisting of but a single cell, which rises 
from the carpogonium laterally from the apex of the latter, and 
does not quite attain the length of the forked hair (gh). It forms 
just about the time when all other parts of the carpogonium have 
attained that degree of differentiation which they possess during 
fertilisation. In the full-grown state, the trichogynium is of the 
same thickness in its entire length, and rounded off suddenly at 
the upper end. The norrow canal of the trichogynium contains 
colourless finely-grained protoplasm. 
Now if antherozoids of Polysiphonia subulata, freshly dis- 
charged by the antheridia of male plants and accidentally carried 
near by currents, come into contact with the upper part of the 
trichogynium, they get firmly attached to the latter. It is par- 
ticularly the apex of the trichogynium which possesses the faculty 
of retaining the globular antherozvid. Then the granular proto- 
plasmic contents of the antherozoids pass into the interior of the 
trichogynium (Fig. 3, s’’). A part of it descends down the 
trichogynic canal into the carpogonium, giving the fertilising im- 
pulse to the central cell of the carpogonium. This process is 
quite similar to the corresponding one in phanerogams. 
As the antherozoids of Floridee are wholly devoid of active 
locomotive organs, the possibility of fertilisation—i.e., the 
coming into contact of the antherozoids and trichogynium—of 
course rests entirely upon a lucky chance. The antherozoids 
reach the female organs passively, either by their own weight, 
or through the currents of the water caused by waves, wind or 
tides, and doubtless in many cases through the incessant move- 
ments of some marine animals. ‘The greater the distance 
between antheridia and carpogonia the smaller, of course, are 
the chances of fertilisation; the more violently the water is 
moved about in the vicinity of and between the separated organs, 
the more probably will the lucky accident of the union of both 
elements take place. 
During a long series of investigations of the reproductive: 
phenomena of Polysiphonia, Dr. Dodel-Port found regularly on 
the bushy thallus, and particularly upon the uppermost and 
younger branches, an enormous number of the well-known stalked 
