1914] MCALLISTER— EMBRYO SAC OF CONVALLARIACEAE 151 



Prantl 



II. Teil. 



5. Abteilung. 1888. 



13. Ernst, A., Chromosomenreduktion, Entwicklung des Embryosackes, und 

 Befruchtung bei Paris quadrifolia und Trillium grandiflorum. Flora 

 91:1-46. 1902. 



14. Ferguson. Margaret C. Two embrvo sac mother cells in Liliiim lonei- 



florum. Bot. Gaz. 43:418-419. 1907. 



onnaire 



Angiospermes. Ann. Sci. Nat. Bot. VI. 13:136-199. 1882. 



16. Lechmere, A. E., Two embryo sac mother cells in the ovule of Fritillaria. 

 New Phytologist 9:257-259. 1910. 



17. Lloyd, F. E., The comparative embryology of the Rubiaceae. Mem. 

 Torr. Bot. Club 8:27-112. 1902. 



18. McAllister, F., The development of the embryo sac of Smilacina stellata. 



Bot. Gaz. 48:200-215. 1909. 



19- , On the cytology and embryology of Smilacina racemosa. Trans. 



Wis. Acad. Sci. 17:599-660. 1913. 



20. Robinson, B. L., and Fernald, M. L., Gray's new manual of Botany. 

 Seventh edition. New York. 1908. 



21. Schniewind-Thies, J., Die Reduktion der Chromosomenzahl und die 

 ihr folgenden Kerntheilungen in den Embryosackmutterzellen der Angio- 

 spermen. Jena. 1901. 



22. Smith, Wilson R., A contribution to the life history of the Pontederiaceae. 

 Bot. Gaz. 25:324-337. 1898. 



2 3« , The tetranucleate embryo sac of Clintonia. Bot. Gaz. 52:209- 



217. 1911. 



24. Wiegand, K. M., The development of the embryo sac in some mono- 

 cotyledonous plants. Bot. Gaz. 30:25-47. 1900. 



EXPLANATION OF PLATES VI and VII 



one-third, 

 fig. 38, w 



figu 



400 



200. Unless otherwise indicated, the 



figu 



Smilacina sessijolia 



Fig. 1. — Embryo sac mother cell recovering from synapsis. 



Fig. 2. — First division of megaspore mother cell. 



Fig. 3. — Four fully separated megaspores arranged bilaterally. 



Fig. 4. — Four fully separated megaspores in an axial row. 



Fig. 5. — The membranes of the homoeotypic division have disappeared, 



leaving only the membrane of the first division. 



Fig. 6. — No traces of membranes remain; the 4-nucleate stage of the 

 embryo sac. 



