23. 
24, 
25. 
26. 
27, 
28. 
29. 
30. 
31. 
32. 
REFERENCE LISTS 107 
Section of archegonial head of a liverwort. 
Section of antheridial head of a liverwort. 
Fern gametophyte bearing antheridia. 
Section of fern gametophyte bearing archegonia. 
Section of fern gametophyte bearing a young sporo- 
phyte. 
Section of fern leaf. 
Sections of fern rhizome, transverse and longitudinal. 
Section of pine ovule, showing embryo-sac. * 
Section of Angiosperm ovule, showing embryo-sac. 
Cross-section of Angiosperm anther, showing arrange- 
ment of sporangia, pollen-sacs, and spores. 
THE END 
