164 



BOTANY. 



depressed and walled in by the overgrowth of the surround- 

 ing tissues; they are thus in reality portions of the general 

 surface. 



291. The walls of the conceptacles are clothed with 

 pointed hairs, which in some species project through the 



Fig. 90.—^, end of branch of a Rookweed (Fucns evanescens), natural 

 size ; /, /, conceptacles. B, magnified section through a conceptaole, allow- 

 ing hairs a, h ; oogones, c ; antherids, e. 



opening, and among these are found the sexual organs, 

 which are themselves, as Sachs has pointed out, modified 

 hairs. The antherids are produced as lateral branches of 

 hairs {A, Fig. 91); each antherid is a thiu-walled cell, 

 whose protoplasm breaks up into a large number of bicili- 

 ate antherozoids, which escape by the rupture of the sur- 



