108 STEIL: SOME NEW CASES OF APOGAMY IN FERNS 
PLATE 5 
Fic. 13. A ventral view of a prothallium of Pellaea adiantoides. The young 
embryo is surrounded by hairs 
Fic. 14. A prothallium of Pélines adiantoides grown in slightly weaker illumina- 
tion than that maintained in the Wardian case. The prt has become dis 
tinctly lobed, and the embryo is developed in the apical reg 
Fic. 15. A similar prothallium of the same species. he lobes are still more 
d the embryo has grown to a larger si 
16. An embryo of Aspidium se scents one Ae of which is on the dorsal 
surface and the other on the ventral surface of the prothallium. The long root is 
also on the ventral surface. 
Fic. 17. A portion of a lobed prothallium of A. hirtipes bearing two embryos, 
each of as has a well-developed leaf and root. 
G. 18. Filaments of a single row of cells of prothallia of A. hirtipes grown in 
weak oes ion. 
FIG - A prothallium of Pteris sulcata, showing the beginning of an embryo in 
the ue sna Tracheids pass upward to the young embryo, which has been pro- 
duced on the inner margin of a | 
Fic. 20. An embryo of A. ee aes beginning its development i in the apical region. 
The ‘ hog region and tracheids are clearly differentiated. 
FIG. ondary prothallia of A. hirtipes produced from the margins and sur- 
faces of a poultice placed in weak light. 
