OOSPORES. 



381 



I The ConfervaeesB, like the (Edogonieae, consist of rcJws of cells or segmented fila 

 ments, which either remain unbranched, as in Chxtomorpha, or become branched, as in 

 g 



\Cladophora, Rhizoclonium, Stigeoclonium (Fig. 3), Draparnaldia, Chxtophora^ . With re- 

 erence to their reproduction, it is only known that macro- and micro-zoogonidia are 

 formed in the cells of the filaments [Chxtomorpha, Cladophora), the sexual significance 

 of which is still unknown^; and that in the other above-mentioned plants resting-spores 

 are formed in certain cells of the filaments. Pringsheim suggests that they are probably 

 equivalent to oospores, but that they are produced parthenogenetically. , 



The Fucace® comprise 

 ^genera of large marine Algae, 



E. FuCOIDEiE. 



in the narrow limitation proposed by Thuret^, a few 

 the thallomes of which, often many feet long, have a 



Fig. \Z\.—Fucus platycarptis (after Thuret) ; A end of one of the larger branches (natural size) ; yy fertile branchlets ; 

 B transverse section of a conceptacle ; d the surrounding epidermal tissue ; a the hairs projecting from the mouth ; b hairs 

 in the interior ; c oogonia, e antheridia (cf. Fig. 2, p. 3). 



greenish-brown colour and a cartilaginous consistency. They are fixed to stones or 

 other bodies by a branched attachment-disc. The thallomes branch dichotomously, 

 and the further development is also frequently forked, but in other cases sympodial, as 

 in Fig. 184. The ramifications, irrespectively of later displacements, all lie in one 

 plane. 



^ [The TJlvacese are probably allied to the Confervacece. In them the cells are arranged so 

 as to form a delicate membrane.] 



2 [According to Areschoug (Nov. Act. reg. soc. sci. Upsal. ser. 3. vol. IX) the microzoogonidia 

 of Cladophora conjugate in pairs.] , 



^ G. Thuret, Ann. des Sci. Nat. II. 1854, p. 197. 



