Lewis. — The Life History of Griffithsia Bornetiana . 655 
in the first-mentioned cell-division described on page 649 (PL LI, Fig. 55). 
When its formation is complete, the primary protuberance divides several 
times vertically. A lateral cytoplasmic process is formed, then the nucleus 
divides by mitosis (Figs. 56, 57). One daughter-nucleus remains in the 
body of the primary protuberance, the other passes into the cytoplasmic 
process. The two protoplasts now become separated by a constriction of 
the Hautschicht, whose ingrowth appears to be aided by the formation of 
a vacuole at the point of constriction (Fig. 57). This process of division 
continues until there are about 200-500 secondary protuberances on the 
apical portion of the terminal cell. 
The protuberances appear not to develop cellulose cell-walls of their 
own, but lie in the swollen wall of the mother-cell (Figs. 58, 59). 
Each of these secondary protuberances gives rise to a branched 
antheridial filament. The single nucleus in each divides by mitosis, and a 
partition is formed separating the two nuclei, and cutting the protuberances 
into an upper and a lower cell. The lower or basal cell buds off other cells 
above, each uninucleate, to the number of five or six (Fig. 59). These, along 
with the upper of the two cells first formed, in turn bud off groups of 
uninucleate cells, which become the spermatia directly (Fig. 60). Thus the 
antheridial filament is a twice compound structure like a small bush, the 
terminal twigs of which become the spermatia. 
The basal cell of the antheridial filament is somewhat cubical is shape 
and may contain ultimately several nuclei. The cells of the first and second 
order of branching are uninucleate and are remarkable for their shape, each 
resembling a pear with a very long stem. These cells early become filled 
with a large vacuole, the cytoplasm forming a very thin film next the 
hautschicht , and the nucleus lying in the apical portion. None of the cells 
of the antheridial filament appear to form a cellulose wall. The whole 
filament is covered by the swollen wall of the mother-cell (Fig. 59). When 
the spermatia are mature, they simply break loose from the cells on which 
they are borne, and float freely out into the water (Fig. 63). As they 
become free, the long neck which attached them to the cell next below 
becomes drawn into the body of the spermatium, which assumes an 
oval shape. 
The mature spermatium is about 3 (jl long and 2/x in diameter. Its 
bulk is occupied by a large vacuole, which is bounded by a thin film of 
cytoplasm. The single nucleus lies in the end which pointed away from 
the antheridial filament. No chromatophores have been discovered in any 
of the antheridial cells. The living spermatium is quite clear and somewhat 
refractive. 
It seems of interest to note the fact that the living spermatia appear 
not to be extruded unless a slight pressure is exerted on the cells of the 
thallus. If branches of an antheridial plant are transferred carefully from 
