CHONDPTTS. 469 



Fig. 20. Longitudinal section of a frond containing a 

 nemathecium. x 43. 



Fig. 21. Section showing the undivided spore mother- 

 cells lying in rows, which are continued into 

 the assimilating filaments. Fresh material, 

 x 10T5. 



Fig. 22. Mass of divided tetrasporangia, surrounded by 

 1he sterile cells in a nemathecium. Fresh 

 material. x 1075. 



Fig. 23. Form of cruciate division of a sporangium. 

 Diagrammatic. 



Fig. 24. Another form of the same. Diagrammatic. 



Fig. 25. Another form of the same. Diagrammatic. 



Fig. 26. Single free tetraspore. It is filled with food 

 material ; the darker portions represent parts 

 of the much divided rhodoplastid. x about 

 3000. 



Plate VI. : The Nemathecium and the 

 Spermophore. 



Fig. 27. Free tetraspore, some time after its escape, and 



surrounded by a wall. In glycerine jelly x 1075. 

 Fig. 28. A tetraspore, having germinated to four cells. 



In glycerine jelly. x 1075. 

 Fig. 29. Germinal product of a tetraspore forming a 



rhizoid-like outgrowth. In glycerine jelly. 



x 1075. 

 Fig. 30. Frond bearing spermophore at its tips. x 2. 

 Fig. 31. Two spermophores. x 12. 

 Fig. 32. Outer layers of the tissue of a spermophore. 



The assimilating cell rows end in antheridia. 



The last cell of each antheridium, the sperma- 



tangium, gives rise to one spermatium. In 



glycerine jelly. x 1075. 



LL 



