39 



each resemljling a pear with a very long stem (fig, 65). 

 These cells early "become filled with a large vacuole, the 

 cytoplasm forming a very tliin film next the ha ut schic ht , 

 and the nucleus lying in the apical portion. None of the 

 cells of the antheridial filament appear to form a cellu- 

 lose wall. The whole filament is covered hy tlie swollen 

 wall of the mother cell (fig, 63). X^Ihen the spermatia are 

 matvu'e, they simply treak loose from the cells on which 

 they are borne, and float freel2^ out into the water, (fig. 

 66) . As they become free, the long neck v/hich attached 

 them to the cell next beloY/ becomes dravm into the body of 

 the spermatium, which assiuaes an oval sha.pe . 



The mature sperma.tium is about 3 M^ long and 2 k/ in 

 diameter. Its bulk is occupied by a large vacuole, which 

 is bounded by a thin film of cytoplasm. The single nu- 

 cleus lies in the end which pointed away from the antherid- 

 ial filament. ITo chroma, tophores haive been discovered in 

 any of the antheridial cells. The living sperme,tium is 

 quite cleitr and somewhat refractive. 



It seems of interest to note the fact that the living 

 spermt-tia appear not to be e:--.truded unless a slight pres- 

 sixre is exerted on the cells of the thallus. If branches 

 of an antheridial plant are transferred carefully from sea- 



