FUCUS VESICULOSUS 107 



(c) Make a drawing of three or four sperms, 

 with the body about 10 mm. long. 



(d) In a similar way, find the fluid exuding 

 from the female conceptacles. What is its 

 color? Mount a drop of it in sea-water 

 and examine with the high power. 



(e) Do you find any oogonia? Any free eggs? 

 If so, how .are the latter freed from the 

 oogonia? Do they possess the power of 

 locomotion? Compare their size with that 

 of a sperm. 



(/) Make a drawing (50 mm. in diameter) of 

 an egg. By the side of the egg draw three 

 sperms to the same scale, showing the 

 relative size of egg and sperm. 



(g) Prepare a mount containing both eggs and 

 sperms, and endeavor, if possible, to fol- 

 low the action of the sperms toward the 

 egg, and the fusion of the two cells. With 

 what act is fertilization completed? 



(ti) Do you consider Fucus a more highly or a 

 more lowly organized plant than Mar- 

 chantia? Give reasons for your answer. 



