198 



REPRODUCTION OF FUCUS 



of germination can be studied by transferring a bit of these two 

 fluids to a drop of sea water on a slide and studying them under a 

 microscope. The differentiation of the gametes of Fucus is an 

 interesting one because it represents the stage where the female 

 gamete has become motionless, but is not retained in the mother 

 cell as in Vaucheria and Oedogonium. 



Fig 124. Female gametangia: A, greatly enlarged view of one of the 

 oogonia shown in Fig. 122, C. The oogonium is dividing and forming the 

 female gametes; p, paraphyses. B, the female gametes discharged but still 

 retained in the inner wall of the oogonium. C, greatly enlarged view of a 

 gamete which is surrounded by male gametes, some of which are seen as 

 dark bodies penetrating the cytoplasm of the female gamete. D, early stage 

 in the germination of the gametospore. See later stage, Fig. 121, C. — After 

 Thuret. 



No resting spores are found among the brown algae. This 

 may be connected with the more uniform conditions that ob- 

 tain in the sea where they are not exposed to the dangers of 

 desiccation as in fresh water forms. It is also noteworthy, that 

 although the reproductive organs are, on the whole, more com- 

 plex, fertilization is of a more primitive character than among 

 many of the green algae, in that the fusion of the gametes is 

 effected outside of the gametangia. 



