47 
Sexuality of the Uredineae. 
at which the conjugate condition arises has yet been made out, but 
according to some recent work of Miss Nichols 1 the point at which the 
transition takes place appears, in this group also, to be different for 
different forms. 
A diagram is given to exhibit the general and cytological life-history 
of the various forms. 
1 Trans. Wiscon. Acad. Sci. xv, 1905. This paper has not yet been seen, but it is quoted 
by Harper in an important work (Sexual Reproduction and the Organization of the Nucleus 
in certain Mildews) which was received too late to allow of its being considered in the present 
article. 
List of Papers. 
1 . Blackman, V. H. : On the Fertilization, Alternation of Generations, and general Cytology of 
the Uredineae. Ann. Bot., xviii, 1904, p. 323. 
2 . : Congo-Red as a Stain for Uredineae. New Phytol., iv, 1905, p. 173. 
2 a. : On the Relation of Fertilization, ‘ Apogamy,’ and ‘ Parthenogenesis.* New 
Phytol., iii, 1904, p. 149. 
3 . and Fraser, H. C. I. : On the Sexuality and Development of the Ascocarp in 
Humaria granulata. Proc. Roy. Soc., Ser. B, lxxvii, 1906, in the press. 
4 . Christman, A. H. : Sexual Reproduction of the Rusts. Bot. Gaz., xxxix, 1905, p. 267. 
5 . Farmer, J. B., Moore, J. E., and Digby, L. : On the Cytology of Apogamy and Apospory. 
Proc. Roy. Soc., lxxi, 1903, p. 453. 
6. Neumann, R. : Ueber die Entwickelungsgeschichte der Aecidien u. Spermogonien der Ure- 
dineen. Hedwigia, xxxiii, 1894, p. 346. 
7 . Richards, H. M. : On some points in the Development of Aecidia. Proc. Amer. Acad, of 
Arts and Sci., xxxi, 1896, p. 255. 
8. Sapin-Trouffy, P. : Recherches histologiques sur la famille des Uredin^es. Le Botaniste, 
5® s6rie, 1896, p. 59. 
