3 i6 BOTANICAL GAZETTE [may 



71. Vaizey, J. R., Alternation of generations in green plants. Annals of Botany 

 4:37 J -378. 1890. 



72. Vines, S. H., On alternation of generations in the thallophytes. Journal of 

 Botany 17:321. 1879. 



73. Williams, J. Lloyd, Studies in the Dictyotaceae. I. The cytology of the 

 tetrasporangium and the germinating tetraspore. Annals of Botany 18:141- 

 160. pis. 9, 10. 1904. 



74. - — , II. The cytology of the gametophyte generation. Annals of Botany 

 18:183-204. pis. 12-14. 1904. 



75. Winkler, Hans, Ueber Parthenogenesis bei Wikstroemia indica (L.) C. A. 

 Mey. (Vorlaufige Mittheilung). Ber. Deutsch. Bot. Gesells. 22:573-580. 

 1904. 



76. , Ueber Parthenogenesis bei Wikstroemia indica. Ann. Jard. Bot. 



Buitenzorg 5:208-276. pis. 20-23. 1906. 



77. Wolfe, J. J., Cytological studies on Nemalion. Annals of Botany 18: 

 607-630. pis. 40, 41. 1904. 



78. Woronin, Helene Wesselowska, Apogamie und Aposporie bei einigen 

 Farnen (Vorlaufige Mitteilung). Ber. Deutsch. Bot. Gesells. 25:85, 86. 

 1007. 



79. - — , Apogamie und Aposporie bei einigen Farnen. Flora 98:101-162. 

 figs. 72. 1907. 



80. Yamanouchi, S., The life-history of Polysiphonia. Bot. Gazette 42: 

 401-449. figs. 3. pis. 19-28. 1906. 



81. - , Sporogenesis in Nephrodium. Bot. Gazette 45:1-30. pis. 1-4. 



1908. 



82. - , Spermatogenesis, oogenesis, and fertilization in Nephrodium. Bot. 



Gazette 45:145-175. pis. 6-8. 1908. 



EXPLANATION OF PLATES IX AND X 



The figures were drawn with the aid of an Abbe camera lucida, under Zeiss 

 apochromatic obj. i.5 mm N. A. 1.30, combined with compensating ocular 18; 

 except figs. 9, 10, 11, 12, 13, 14, 20, 21, 28a drawn with compensating ocular 4; 

 and figs. 28, 26, and text cuts drawn under combination of dry obj. 4 mm and 

 ocular 4. The plates and text cuts are reduced to one-half the original size. 



Figs. 1-3 are in the text. 



PLATE IX 



Fig. 4. — Nucleus of vegetative cell of an apogamous prothallium; spirem 

 formed; two nucleoli present. 



Fig. 5. — Late prophase; long slender chromosomes present, previous to 

 their arrangement in an equatorial plate. 



Fig. 6. — Metaphase; two daughter halves of each chromosome just separated. 



Fig. 7. — Late anaphase; daughter chromosomes grouped at two poles. 



Fig. 8. — Polar view of late anaphase; 64 chromosomes present in a group. 



