266 



BOTANY. 



be still regarded as portions of the general surface, and the 

 cells which form, the inner surface of the conceptacles con- 

 stitute a continuation of the epidermal tissue of the thallus. 

 353. The walls of the conceptacles are clothed with 

 pointed hairs, which in some species project through the 



Pig. \&\.Fucu8platycarpu8, A, end of a portion of thallus ; /,/, cpnceptacles in 

 fertile branchlets. , vertical section through a conceptacle ; a, hairs projecting 

 from the mouth ; b, cavity of conceptacle nearly filled with hairs ; c, oogonia ; e, an- 

 theridia ; rf, epidermal tissue of thallus. After Thuret. 



opening, and among these are found the sexual organs, 

 which are themselves, as Sachs has pointed out, modified 

 hairs. Some of the species are monoecious, while others are 

 dioecious. In the monoecious species the antheridia and 

 oogonia occupy the same conceptacle (B, Fig. 181) ; the 

 antheridia are produced as lateral branches of modified hairs. 



