aller 
still more distant from each other, while in longitudinal section they appear as 
long cells having their long axis parallel to the longitudinal axis of the frond. The 
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HY ets: 
LP ap ape © 
Se FR & æ o 
EP CB > Ze 2 
PE æ Ba, 
Fig. 474. 
Gigarlina mamillosa. Transverse section of frond. 560: 1. 
cells of the inner cortex and of 
the medullar tissue may produce 
long thin cell-filaments consisting 
of long cells, which grow out in 
a transverse direction downwards 
between the primary cell-rows 
and may be con- 
nected with these through second- 
ary pits (fig. 475). 
The sex organs have not 
been observed by me. The an- 
theridia were described by Burr- 
HAM in 1896. The male plant, 
according to this author, differs 
much from the female one, “for 
sometimes 
it is thickly beset from near the base with flattened leaf-like branches arising just 
within the edges of the main portions of the frond, and with smaller ones from 
Fig. 475. 
Gigartina mamillosa. A, longitudinal section of frond. 560:1. B, longitudinal section 
of medullar tissue. 350 : 1. 
the other portions of the thallus”. 
In some of these leaf-like branches the an- 
theridia appear. The male plant was found in September; BORGESEN found antheridia 
