Lewis . — The Life History of Grijfithsia Bornetiana. 673 
Vegetative Multiplication. 
Griffithsia Bornetiana may reproduce itself vegetatively in two ways : 
first, by accidental isolation and subsequent growth of single cells or small 
pieces of a filament ; second, by the production of new plants from tendrils. 
The first method of propagation was described for G. Corallina by 
Janczewski (43) and mentioned as occurring in G. Bornetiana by Farlow (29). 
More recently Tobler (82, 83, 84) has called attention to the fact that 
Griffithsia , Bornetia , Dasya, Polysiphonia % and other forms may reproduce 
themselves under laboratory conditions by a process of fragmentation 
of the filaments and growth of the resulting portions into new plants. 
In G. Bornetiana this process takes place not rarely in nature. In such 
cases the isolated cell produces a rhizoid from its base and a new 
growing point from its apex (Figs. 139, 140). The rhizoid is formed 
normally in the manner already described. The apical cell is produced by 
the accumulation of protoplasm at the tip and subsequent unequal 
division of the parent cell in the usual manner. 
Vegetative propagation by means of tendrils has been described on 
page 653- 
Germination of Spores. 
The spores germinate readily in the laboratory. If a mature tetra- 
sporic or cystocarpic plant be placed in sea-water over night, young 
sporelings up to the 3-celled stage will be found abundantly attached 
to the bottom and sides of the vessel the next morning. Many of the 
stages of germination here described were collected in the field under 
natural conditions, but the majority of the figures given, especially of 
the younger stages, were taken from material cultivated in the laboratory. 
The similarity of the structure of the carpospores and the tetraspores 
has been noted above ; the phenomena of germination are also practically 
the same in the two kinds of spores. On being released, the spores become 
spherical and settle slowly in the water. They appear to become attached 
to the surface of any solid body they touch, such as rocks, glass, other algae, 
and even such soft bodies as the gelatinous substance enclosing chains 
of diatoms. 
During the progress of germination, soon after the spore becomes 
attached, there is formed around it a cellulose wall of the usual type, which 
becomes tolerably thick, especially around the basal region of the sporeling. 
At the same time, numerous starch-grains also become visible in the 
cytoplasm of the spore. Several hours after the spore is shed the nucleus 
divides by mitosis. During this time there is no noticeable change of shape 
in the spore. 
