596 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Macrosporangia of Selaginella.* — E. Kainradl records a macro- 

 sporangium of Selaginella helvetica with several spore-tetrads, and 

 describes his investigations on the macrosporangia of his native species. 

 In S. helvetica, the author found many examples in young macrosporangia 

 of the development of two equal spore-tetrads ; and in other cases he 

 found, together with a normal spore-tetrad, traces of tetrad division in 

 a sterile sister-cell. In one young macrosporangium all the cells of the 

 sporogenous tissue were markedly large, rich in protoplasm, and thick- 

 walled. One ripe macrosporangium contained four well-developed 

 spore-tetrads, as well as numerous smaller withered tetrads. The author 

 goes on to discuss the homology of the male and female sporangia, and 

 the gradual reduction in the latter of the number of macrospores which 

 has arisen in the course of their phylogenetic development. He further 

 points out that macrosporangia provide more structural material than 

 microsporangia. The further abnormalities in S. helvetica of a macro- 

 sporangium with three macrospores, and the not infrequent dichotomous 

 branching at the apex of a sporangial spike, are mentioned. 



Selaginella in Papuasia.f — G. Hieronymus publishes descriptions 

 of 18 new species of Selaginella from east New Guinea, with some 

 general remarks on the occurrence of the genus in Papuasia. The 

 plants were collected by Schlechter, Lauterbach, Burke, and others. 

 The descriptions are much more than mere diagnoses, and record 

 minute morphological details. 



North American Ferns. — T. C. Frye and M. M. Jackson J give 

 an account of the fern-allies of Washington, with descriptions, keys, 

 and figures. The following genera are comprised in the paper : Lyco- 

 podium (with 8 species), Selaginella (3), Isoetes (7), Equisetum (8). 

 In Isoetes the structure of the leaves and the sculpture of the spores, 

 are the main characters for distinguishing the species. 



E. J. Winslow § describes some instances of double sori in North 

 American species of Athyrium, and discusses the question of the relation- 

 ship of the straight simple sorus of Asplenium, the double sorus of 

 Diplazium, and the horse-shoe shaped sorus of Athyritcm, and further 

 the relation of the reniform sorus of Dryopteris. 



Chinese Ferns. || — 0. Christensen publishes a list of the ferns 

 collected in Kouy-Tcheou by J. Esquirol in 1910-11. The province is 

 extraordinarily rich in species. Fifty three species are enumerated with 

 annotations ; three are new to science, and their characteristic structure 

 is described. 



* SB. k. Akad. Wiss. Wien, Math.-Natur. Kl., cxxi. (1912) pp. 651-65 (1 tab. 

 and 2 text-figs.). See also Bot. CentralbL, cixiii. (1913) p. 311. 

 t Engler's Bot. Jahrb., 1. (1913) pp. 1-45. 

 J American Fern Journ., iii. (1913) pp. 65 -83 (4 pis.). 

 § American Fern Journ., iii. (1913) pp. 88-92 (figs.). 

 ;il Bull. G6ogr. Bot., Le Mans, xxiii. (1913) pp. 137-43. 



