Heltt t it ithocladiece 



37 



stones or wood by a number of thick old shoots ; these send off 

 numerous primary axes which float freely in the water. Tin- 

 primary axis consists of a central filament of cells which grows by 



Fig. 1. A, Batrachospeninan monilit'orine Both, from Malham Cove, W. Yorks. ( x 2); 

 B C, Batrachospermum vagum (Both) Ag., from Thursley Common, Surrey: 

 B ( x 2) ; C, single node with lateral branches, more highly magnified. D, ger- 

 minating spore. E, protonemal growth. F, Female organ and fertilization; 

 s, spermatium; c, carpogonium ; t, trichogyne. (D, E, and F after Schmidle.) 



means of a hemispherical apical cell. The cells of this central 

 filament become swollen at each end, a dense whorl of branches 

 being produced at each swelling (or node). From the basal cells 



