RECENT ADVANCES IN SCIENCE 45 



has been shown to obtain between the different whorls, and it 

 is pointed out that this is inconsistent with the view that 

 supernumerary perianth members are the outcome of trans- 

 formation of stamens. The perianth is regarded as having 

 been derived either entirely from bracts, or in part from these 

 and in part from stamens. 



Taxonomy. — E. D. Merrill has described a new species of 

 Oreomyrrhis from Mount Kinabalu which adds another to the 

 already known Australian types from that locality {American 

 Journ. Bot.). To the same journal J. C. Arthur contributes 

 the final portion of his paper on the Uredinales of Guatemala, 

 in which 9 new species of Puccinia are described, and also addi- 

 tions to the form genera Uredo (4 spp.) and Aecidium (2 spp.). 

 In the Journal of Botany for January Canon Bullock- Webster 

 describes a species of Nitella, closely allied to N. flexilis from 

 Lough Shannagh. In the concluding parts of his paper on 

 the genus Manettia, Dr. Wernham describes 26 further 

 species. 



Seven additions to the genus Sedum are diagnosed by 

 Praeger, and Miss Lister describes two new varieties of Lam- 

 proderma. 



Three new species of Phyllanthus are described by Fawcett 

 and Rendle. J. F. Rock adds five more species to the genus 

 Cyrtandra and several varieties all from Hawaii {Amer. Journ. 

 Bot. Feb. 1919). 



New species of Carmichcelia have been described by Prof. 

 Cockayne {Trans. N.Z. Institute, vol. 1.). 



S. F. Blake {Contrib. Gray Herb. 19 18, 53) has described 

 several new genera belonging to the Flacourtiaceae {Hecato- 

 stemon), Composite {Oxycarpha), and Loasaceae {Schismocarpus), 

 and a number of new species. In the same journal J. F. 

 MacBride describes new species of Tricyrtis, Atriplex, Cirsum, 

 Lomatium, Lotus and Lycium. 



Heredity and Genetics. — A most useful summary of the pre- 

 sent state of knowledge of heredity and variation in Pisum 

 with a bibliography of over 100 papers, has been compiled by 

 O. E. White {Mem. Brooklyn Bot. Garden, No. 19). In the 

 introductory matter this author lays stress on the importance 

 of recognising that the so-called " characters " are the visible 

 expression, not of the hereditary factors alone, but a combined 

 effect of these and the environment. For each group of 



