THE FERX BULLETIN 



2 7 



Under ordinary conditions fern spores of the species 

 experimented with will not germinate in darkness. 

 Germination was best in light of medium intensity. 

 Weak light produces filamentous prothallia and 

 stronger light the usual heart shaped forms. 



Pfeifer, W. M. Differentiation of Sporocarps in 

 Azolla illust. Botanical Gazette, D. 1907 — Mega- 

 sporocarps and microsporocarps develop alike for 

 some time. The microsporocarp results from the 

 abortion of the megaspores. 



Pierce, W. C. Ferns, illust. Floral Life, D. 1907 — 

 The forms of Xephrolepis exaltata discussed from 

 the cultural viewpoint. 



Underwood, L. M. The Xames of Some of our Na- 

 tive Ferns. Torreya. O. 1907. — Calls attention to 

 several new combinations that the publication of 

 Christiansen's "Index'' makes possible. 



Underwood, L. M. American Ferns. — VII. The 

 American species of Stenochlaena. Illust. Torrey 

 Bulletin 1907. — An account of the American species 

 which are regarded as 12 in number. Includes a de- 

 scription of three new species. ^. angustata from 

 Columbia 5. Jamaicensis from Jamaica and vS\ 

 Maxoni from Costa Rica. S. Kunzeana is reported 

 from southern Florida. 



Woodburn, W. L. A Remarkable case of Poly- 

 spermy in Ferns, illust. Botanical Gazette, S. 1907. 



Yamananouch, S. .Sporogencsis in Nephrodiitm, 

 illust. Botanical Gazette, Ja. 1908. — A preliminary 

 paper to one on apogamy. The conclusion is drawn 

 that there is a uniform number of chromosomes and 

 in the normal life-history a reduction of chromo- 

 somes in sporogenesis. 



