Davis. — The Fertilization of Batrachospermum. 75 
Fig. 8. Illustrates an instance where the point of fusion is very small. 
Fig. 9. Fertile filaments beginning to develop from the carpogonium. 
Fig. 10. Shows peculiar and very exceptional position of the nuclei of the 
trichogyne and antherozoid. 
Fig. 11. Nucleus of antherozoid near point of fusion. 
Fig. 12. Nucleus of antherozoid having passed into the upper portion of the 
trichogyne. 
Fig. 13. Illustrates fragmentation of nucleus in trichogyne and antherozoid. 
Fig. 14. Nucleus of antherozoid breaking up into many small fragments. 
Fig. 15. Nucleus of antherozoid in many small fragments, probably derived 
from such a condition as that shown in Fig. 14. 
Fig. 16. Two nuclei in fused antherozoid. 
Fig. 17. Shows manner in which fertile filaments grow downward from the 
carpogonium (c) ; prominent nucleus from antherozoid in upper portion of the 
trichogyne. 
Fig. 18. Portion of a mature cystocarp showing trichogyne (t) and antherozoid ; 
each containing its original nucleus ; s, developed spores. 
Batrachospermum coeru lessens , Sirdt. 
Figs. 19-23 drawn from living specimens. 
Fig. 19. Carpogonium with very young stage of trichogyne ; illustrates distribu- 
tion of chromatophore in that structure. x 2400. 
Fig. 20. Half-developed trichogyne with chromatophore extending from the 
carpogonium. x 1600. 
PLATE VII. 
Figs. 23-32 drawn from glycerine preparations of specimens fixed with absolute 
alcohol and stained with Mayer’s acid haemalum, magnification 1600 diameters. 
Fig. 21. Mature trichogyne with chromatophore-derivative. xnoo. 
Fig. 22. A peculiar instance where the trichogyne-cell has continued to grow 
forward and has divided into two cells. x 1600. 
Fig. 23. Trichogyne still connected with carpogonium. 
Fig. 24. Nucleus of antherozoid lies in a position farthest removed from point 
of fusion. 
Fig. 25. Nucleus of trichogyne lying very near the top of that structure. 
Fig. 26. Nucleus of antherozoid having passed into the trichogyne. 
Fig. 27. Nucleus of trichogyne having passed into the antherozoid, probably 
derived from a condition of affairs such as is shown in Fig. 25. 
Fig. 28. Illustrates fragmentation of nucleus of the trichogyne. 
Fig. 29. A condition similar to Fig. 28, except that the nuclear fragments 
in the trichogyne are widely separated ; antherozoid near base of trichogyne. 
Fig. 30. Shows fragmentation of nucleus of the antherozoid. 
Fig. 31. Fragmentation in both trichogyne and antherozoid. 
Fig. 32. A half-developed cystocarp; /, trichogyne with nuclear fragments; 
c, carpogonium ; s , short sterile branches. 
