446 EXPLANATION OF THE FIGURES. 



FIG. 



3. A ripe spore beginning to germinate, three days after sowing, x 300. 



5 — 9. Germinating spores more developed; six days after sowing, x 100. 



Tig. 6 is fig. 5 turned round 45° ; fig. 7 is the same object turned round 



90°; fig. 8 turned round 270°. 

 10. A germinating spore whose first capillary root is just breaking through the 



exosporium, x 300. 

 11 — 14. Sections of spores more advanced in germination ; figs. 11 and 14 seen 



from above, figs. 12 and 13 from the side. Figs. 11 — 13 are magnified 



300, fig. 14, 150 times. Figs. 13 and 14 represent spores eleven days 



after sowing. 



15. Fore-end of a somewhat more developed germ-plant, 36 days after sowing, 



seen from above, X 200. 



16. Longitudinal section of a similar fore-end, x 200. 



1 7. Fore-end of a germ-plant 42 days after sowing, x 200. 



18. Germ-plant 49 days after sowing, x 30. 



19 — 22. Half-developed spring shoots of fertile specimens, X 5. 



23. Half-developed spring shoot seen from above, x 200. 



24, 25. Longitudinal section, perpendicular to the surface, of half-developed 



shoots of fertile plants— fig. 24, x 200 ; fig. 25, x 400. 

 26, 27. Longitudinal section, perpendicular to the surface, of young shoots of 

 barren plants, x 200. 



28. Transverse section of an older shoot of a barren specimen which bears four 



rudiments of adventitious shoots. Very delicate fungoid threads are 

 seen upon the outer surfaces of the epidermal cells of the mother-shoot. 

 X 200. 



29. Longitudinal section of a rudimentary antheridium, x 300. 



30. Longitudinal section of an unusually slim antheridium almost ripe. The 



contents of the cells, and the mother-cells of the spermatozoa, are not 



shown, x 200. 

 31°'*. Mother-cell of spermatozoa from an unripe antheridium, x 600. 

 32"'*. The same after its escape from a ripe antheridium. The included spiral 



spermatozoon is already revolving, x 600. 

 33«, M Free spermatozoa, killed by iodine. In 33" and 33 c the mother-cell is 



attached to the hinder end. x 600. 



PLATE V. 



PELLIA EPIPHYLLA. 



1. Vertical longitudinal section of a shoot bearing the rudiments of archego- 



nia, X 30. 



2. A similar shoot with more developed archegonia, x 30. 



3. Longitudinal section of a very young archegonium, x 400. 



4. Longitudinal section of the upper end of a somewhat more developed 



archegonium, X 300. 



