168 SEAWEEDS 
clonium. They are of similar origin to the gametes, 
but have four cilia. In Uvrospora they have a long 
tail, and looked at endways, they are four-sided with 
sharp angles, but they appear to possess the power 
Fic. 51.—Urospora penicil’iformis. a, filament; b, escape of gametes; e, 
part of filament more highly magnified than @; 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 
