48o BOTANICAL GAZETTE [june 



Summary 



1. The gametophyte generation of Pteris sulcata L. is ordinarily 

 produced by the germination of a spore. 



2. The embryo sporophyte is of apogamous origin. 



3. The gametophyte generation of Pteris sulcata under certain 

 conditions was produced aposporously. 



4. The gametophytic portions or gametophytes were formed in 

 connection with the lamina or the petiole of the primary leaf. In 

 one instance a prothallium was produced from both lamina and 

 petiole of the primary leaf. A sharp line of demarcation usually 

 exists between the cells of the gametophyte and the sporophyte. 



• 5. The prothallial portions developed antheridia, secondary 

 prothallia, and in one instance a sporophyte-Hke outgrowth. 



6. The antherozoids, produced by the aposporously developed 

 prothallia, were actively motile and normal" in appearance. 



7. Occasionally forms intermediate in character between game- 

 tophyte and sporophyte were formed. 



8. It seems probable that the origin of the aposporously pro- 

 duced gametophyte may be traced to an early stage in the 

 development of the embryo. Since the embryo, on account of its 

 apogamous origin, is intimately connected with the prothallium, 

 it is not impossible that in some way cells of the prothallium may 

 be embodied in the developing embryo. These cells, retaining the 

 power to divide, may produce such outgrowths as have been 

 described. 



LITERATURE CITED 



1. Bar"^, a. de, tjber Apogamie Fame und die Erscheinung der Apogamie im 

 Allgemeinen. Bot. Zeit. 36:449-487. pi. 14. 1878. 



2. Bower, F. O., On apospory in ferns. Jour. Linn. Soc. 21:360-368. pis. 

 10, II, figs. 5. 1884. 



3. , On some normal and abnormal developments of the oophyte of 



Trichomanes. Ann. Botany 1:269-305. pis. 14-16. 1888. 



4. , Attempts to induce aposporous developments in ferns. Ann. 



Botany 4:168-169. 1889. 



5. DiGBY, L., On the cytology of apogamy and apospory. II. Preliminary 

 note on apospory. Proc. Roy. Soc. 463-468. 7?g-J- J- 1905. 



6. Druery, C. T., Observations on a singular development in the lady-fern. 

 Jour. Linn. Soc. 21:354-360. 1884. 



