252 



PLANT STCDIKrt 



produced by oceanic currents and forming tlie so-called 

 " Sargasso seas," as that of tlie North Atlantic. 



Fio. 220. A iiortiiiii (if .-i Inn 

 into stem-like niid Iciiriil 



NETT and MlIKItAV. 



' pofljiHls, ami ; 



hnwiiii; llic thallns ilifl'iTrntiatrd 

 • hladdcr-like flciats— Aflcr Hkn- 



171. Reproduction. — The two main groups of Thrown 

 Algse differ from each other in tlicir reproduction. One, 

 represented by the Laminaria.s and a, nia,j(irity of the fdrms, 

 ])roduces zoospores and is isogamous (l^'ig. 217). The zoo- 

 si)ores and gametes are peculiar in having the two cilia, 

 attached at one side rather than at an end ; and they re- 

 semble each other very closely, except that the ganu>tes 

 fuse in jDairs and form zygotes. 



