MORPHOLOGY. 



sinks into the protoplasm of the egg cell, makes its way to the nucleus of 

 the egg, and fuses with it as shown in fig. 181. The fertilized egg then 

 grows into a new plant. Nearly all the brown algae are marine. 



Fig. 178. 



Antheridia of Fucus, on 

 branched threads. 



Fig. 179- 



Antheridia of Fucus with 

 leaping spermatozoids. 



Fig. 1 80. 



Eggs of Fucus surround- 

 ed by sparraatozoids. 



Fig. 181. 



Fertilization in Fucus; fn, female nucleus; mn, male nucleus; M, nucleolus. In 

 the left figure the male nucleus is shown moving down through the cytoplasm of the 

 egg; in the remaining figures the cytoplasm of the egg is omitted. (After Stras- 

 burger. ) 



367. The Gulf weed (Sargassum bacciferum) in the warmer Atlantic 

 ocean unites in great masses which float on the water, whence comes the 

 name "Sargassum Sea." The Sargassum grows on the coast where it is 

 attached to the rocks, but the beating of the waves breaks many specimens 

 loose and these float out into the more quiet waters, where they continue 

 to grow and multiply vegetatively. 



368. Uses. Laminaria japonica and L. angustata are used as food by 

 the Chinese and Japanese. Some species of the Laminariaceae are used as 

 food for cattle and are also used for fertilizers, while L, digitata is some- 

 times employed in surgery. 



