2i8 PRACTICAL BOTANY 



The oogonia, or female organs, are most easily observed, 

 being spherically enlarged cells of the filament, borne singly or 

 several together : in such oogonia note 



i. The rupture of the cell-wall at the period of maturity by a 

 transverse slit. 



ii. The beak-like canal, which projects in some species from 

 the slit. 



iii. The hyaline receptive spot. 



iv. In old oogonia the mature oospore with thick wall, and 

 dense contents. 



The antheridia, which are smaller and shorter cells than 

 those of the normal filament : each divides into two cells, the 

 contents of which, without further division, escape as a motile 

 yellow sperxnatozoid similar in form to the swarm-spore. 

 Attempts should also be made to observe the germination of 

 the oospore. 



