560 Transactions. 
that the reproductive organs may be found at any time of the year, though 
i i mo In specimens collected at the end of March 
both ripe and immature oogonia were found, and also in others collected in 
September. 
The male conceptacles (fig. 15) possess many more hairs, and they are 
much more branched, and more strongly developed. One hair (fig. 15) 
arising just opposite the ostiole extended almost to the ostiole itself, and 
was densely covered with branches, which were also branched, thus present- 
ing the appearance of a small tree with monopodial branching. 
The antheridia are formed usually on branched hairs from the swollen 
ends of the branches. They are much smaller than the oogonia, and the 
rotoplasm is rounded off into numerous small colourless spermatozoids. 
Occasionally small unbranched hairs develop directly into antheridia. The 
spermatozoids escape into the surrounding water, still enveloped in an inner 
mucilaginous coat, which is dissolved by the water, setting free the actively 
swimming spermatozoids. 
walls surroun the organs are dissolved, setting free the oospheres and 
spermatozoids. Each oosphere when set free becomes rounded off, and is 
SUIT ed by numerous spermatozoids carried to it by the water from a 
PECULIAR MORPHOLOGICAL FEATURES. 
External Markings. 
On the stipe and lower part of the lamina are to be found curious 
markings, which seem to be cracks in the tissue. On the stipe these are 
usually seen on only one side, and are about 1-5 mm. in depth. The 
and these pits are found usually on the upper surface, so that when the 
plant is left uncovered by the water, and the weight of its fronds are 
stant dashing of the water upon it, and these pits give greater protective 
pliability to the stipe. ee 
There are smaller linear markings on the lower expanded portion of 
the frond; these are more numerous, forming a very regular pattern- 
