1G8 



SEAWEEDS 



donium. They are of similar origin to the gametes, 

 but have four cilia. In Urosrpom they have a long 

 tail, and looked at endways, they are four-sided with 

 sharp angles, but they appear to possess the power 



FIG. 51. Uro*pora penicil-'iformis. a, filament; ft, escape of gametes; e, 

 part of filament more highly magnified than a ; d, zoospores ; e, gametes highly 

 magnified, c, d, e, after Areschoug. 



of altering their shape somewhat, so that the sides are 

 now concave, now convex. 



In Gomontia the sporangia are larger than the 

 ordinary vegetative cells, and the zoospores have only 

 two cilia. There are also produced in this genus 



