EXPLANATION OF THE PLATES. 



PLATE I. 



Fig. 1. Prothallus of Sphagnum cuspidatum (after Hofmeister). 

 Fig. 2. Archegonium of Phascum, showing the embryonic cell with 

 its nucleus just after impregnation, magnified (after Hofmeister). 



Fig. 3. Antlii lidium and paraphyses of Mnium punctatum, magni- 

 fied. The antheridium is ejecting the spermatozoids. 

 Fig. 4. Antln ridiura of Sphagnum (after Hofmeister). 

 Fig. 5. Perforated leaf-cells of Sphagnum, containing a spiral 

 thread, and surrounded by narrow chlorophyllous cells, magnified. 



Fig. 6. Perforated cells of Leucobryum glaucum, enclosing chloro- 

 phyllous cells. 



Fig. 7. Section of upper part of sporangium of Phascum cuspida- 

 tuin, magnified (after Lautzius-Beninga). 

 c. columella. 

 *. spore- sac. 

 a. walls of spore-sac. 

 i. intermediate space. 

 m. inner wall of intermediate space. 

 k. outer wall of intermediate space. 

 w. wall of sporangium. 



