PUOAGEJE. 



367 



{A, Pig. 182) ; each antheridium is a thin-walled cell, whose 

 protoplasm breaks up into a large number of bi-ciliate sper- 

 matozoids, which escape by the rupture of the surrounding wall 

 (B, Pig. 182). Before rupturing, however, the antheridia 

 detach themselves and float in the water with their contained 

 spermatozoids. 



354. — The oogonia are globular or ovoid short-stalked 

 bodies, which develop from papillae on the wall of the con- 

 ceptacle. As each papilla elongates, it becomes divided into 



!Fi^. 182. — Fucus vesiculosus. -4, branched hair bearing antheridia, a. B, sperma- 

 tozoids. 7.. og^ oogonium, with contents divided into eight parts ; p, paraphyses, or 

 surrounding hairs. //., commencement of the escape of the oospheres— the outer 

 wall, a, of the oogonium has burst, the inner, i, is ready to open. III., oosphere es- 

 caped, and surrounded by i-permatozoids ; IV.y K, germination of the oospore. S 

 X 330, all the rest 160. -After Thuret. 



a basal and an apical portion by a transverse partition ; the 

 apical part enlarges, and (in the genus under consideration) 

 its protoplasm divides into eight portions (/, Fig. 182), 

 which eventually become spherical ; it is thus an oogonium 

 containing eight oospheres. The oospheres escape from the 

 oogonium surrounded by an investing membrane, which floats, 

 out through the opening of the conceptacle, where it finally 

 ruptures and sets the oospheres free {II, Pig. 182). The 

 spermatozoids and oospheres ar5 liberated at about the same 



