BROWN ALGM 31 



nium contains a solitary female gamete. One male gamete 

 fuses with the stationary female gamete in the archegonium 

 to form a zygospore which is parasitic on the parent plant 

 for a time. 



BLUE-GREEN ALG! 



Gloeocapsa is a unicellular blue-green alga, which some- 

 times forms groups of cells; in all cases the cells and groups 

 are surrounded by a gelatinous layer. 



Nostoc is a filamentous blue-green alga which often forms 

 large spherical colonies. The filaments are made up of 

 vegetative cells which are separated by slightly larger color- 

 less cells or heterocysts. The breaking up of the filaments 

 occurs at the points of union of the heterocysts and vegeta- 

 tive cells. 



BROWN ALGJE 



Plant Body. The plant body of fucus is a dichotomously 

 branched or forked thallus, the cells contain chlorophyll but 

 the green color does not appear because of the brown of 

 phycophcein, a brown color. In fucus the male reproductive 

 organs occur on one thallus and the female on another, so 

 that fucus is dioecious. 



Male Thallus. The point of the thallus in contact with the 

 rock is the hold-fast, above the hold-fast is the rounded stem- 

 like part of thallus, this united to the broad leaf-like part 

 which has large air cavities, or vesicles which act as floats, 

 and during the reproductive period the swollen ends contain 

 numerous conceptacles with the antheridial hairs; these have 

 numerous antheridia with sperms which are set free in the 

 conceptacle and later swim out into the water by means of 

 two cilia. 



