small raised portion of the surface of the prothallium, 
which grows more elevated as it developes, until it 
finally becomes a conical protuberance, at the base of 
which is the Germ-cell containing the young germ. 
• 
Above this germ-cell is a second cell filled with a 
mucilaginous fluid, which after a time swells, and 
forces a passage through the apex of the archegonium, 
around which it collects. 
The antheridium first appears as a large circular cell 
enclosed in a projecting portion of the surface of the 
prothallium. A quantity of smaller cells can soon be 
observed in the interior of the larger one, each of which 
contains a coiled up filament called an Antherozoid . 
These antherozoids are, in course of time, set at liberty 
by the bursting of the surrounding cells ; and when 
unfolded, are minute, thread-like bodies, furnished at 
their smaller extremity with several long arms or Cilia . 
On issuing from their cells, the antherozoids rotate 
and appear to be endowed with the power of indepen¬ 
dent motion, which is believed to be due to the before- 
mentioned cilia. As they move across the surface of 
the prothallium, many of them are retained by the 
mucilage collected round the orifice of the archegonium, 
and by its means, find their way along the passage to 
the germ. . This is fertilized by contact with the 
antherozoids, and from it a young plant begins to 
grow. 
Some time after fertilization the prothallium decays 
and dies away. It may frequently be observed attached 
to the young plant. 
