396 



BOTANY OF THE LIVING PLANT 



i^'-S- 334)- Ij^ structure the zoospore shows the ciha in pairs, each 

 pair related to a nucleus which is superficial, while the chloroplasts 

 lie within. The origin and structure of the zoospore suggests that 



.Mite 



Fig. 334. 

 l'aiu]ieyia scs^ilis. .4 — young sporangium. t'=zoobporc, with tht; spuraugiuui 

 from which it has escaped. C=a portion ot the peripheral zone of a zoospore. 

 /J — a young plant, with rhizoids, developed from a zoospore. {A, B, after Gotz ; 

 jL* after Sachs : C after Strasburger.) (From Strasburger.) 



it represents the undivided contents of a whole sporangium, such as 

 may be seen in other Siphonales. 



The Siphonales and Siphonocladiales rcprotluce sexually ; but 

 degrees of difference in size of the gametes are seen. The differentia- 

 tion thus indicated must be held as distinct from, though parallel 

 with that already described in the Brown Algae, and in the Ulothri- 

 cales. In Acetabidaria the gametes are of equal size, and those 

 produced from different sporangia, or from different plants fuse in 



