PH&OSPORE& 



255 



observed. As the Cutleriaceae present an approach towards the Fucaceae, 

 so the Dictyotacese may possibly indicate the point of departure of the 



FIG. 230. Padina Pavonia Gaill. a, natural size ; b, portion of surface of thallus with tetrasporanges ; 

 c, transverse section of upper portion of thallus; d, of lower portion (x 100). (After Kiitzing.) 



Florideae, agreeing with that order in the presence of tetraspores and of 

 non-motile pollinoids ; but as the oogone presents no indication of even a 

 rudimentary trichogyne, and there is no process analogous to the forma- 



FIG. 231. Stages in the formation of the tetraspores in Padina. Pavonia (magnified). (After Reinke.) 



tion of a cystocarp, it seems best, until more is known of the process of 

 fertilisation, to retain the Dictyotacese as an aberrant order of Phseosporese, 

 with which they also agree best in the nature of their pigment. 



