8o FUCUS VESICULOSUS. 



conceptacles, in the place of the oogonia we find little masses 

 of protoplasm growing on the sides of the hairs, rather than at 

 their bases, known as antheridia or male organs of reproduc- 

 tion as seen at a, fig. 6. 



At D, fig. 6, we see one of the antheridia more highly magnified, 

 showing the great numbers of antherozoids as they float in the 

 water ; little pointed bodies with a distinct, bright red spot at 

 one side and furnished with two very active cilia, one extend- 

 ing forward and the other back. The antherozoids are fully 



Fig. /. Fucus Serratus. Natural size. 



developed at the same time the oospheres are thrown out of 

 the conceptacle ; and there seems to be some attractive power 

 in the oospheres, or in the paraphyses around the mouth of the 

 conceptacle, for the moment the oosphere leaves its home it is 

 attacked by swarms of the antherozoids. They seem to attach 

 themselves firmly by means of the anterior cilia, while the poste- 

 rior is in active motion. In this way they give to the oosphere 

 a rapidly whirling motion, which lasts for nearly half an hour. 

 It then becomes quiet, and very soon a change is seen. It is 

 supposed that the oosphere comes to a rest so soon as an anthe- 

 rozoid forces its way through the membrane into the proto- 

 plasm ; the primitive change in the oosphere is a semblance 



