﻿CURRENT LITERATURE 



Columbia— E. de Wildeman (Rep. Sp. Nov. 13:369-384. 1914) has pub- 

 lished 35 new species and varieties of flowering plants from Central Africa 

 and characterizes two new genera, namely Brieya of the Anonaceae and 

 Giorgiclla of the Passifloraceae. The same author (Bull. Jard. Bot. Brux. 

 4:1-241. 1914) in cooperation with specialists has issued "Additions a la 

 flore du Congo." Several species new to science are included and the fol- 

 lowing new genera are proposed: Volutellopsis and Gilletia Torrend of the 

 Mucedinaceae.— G. W. Wilson (Mycologia 6:192-210. pis. 135, 136. 1914) 

 in continuation of his studies on the Peronosporales describes several new 

 species and propose as new genus (Bremielkt) based on Peronospora mega- 

 sperma A. Berlese. — L. Wittmack (Bot. Jahrb. 5o:539"555- iQH- Supple- 

 ment-Band) has published 6 new species of Solanum from South America.— 

 X. Woroxichix (Bull, fur Ang. Bot. 7:431-44°- pi- ^o. 1914) describes and 

 illustrates a new fungus {Plectodiscella piri) found in the Kaukasus. The 

 genus is said to represent a new family, namely the Plectodiscelleae.— C. H. 

 Wright (Bull. Kew p. 330. 1914) has published a new species of Hippeastrum 

 (H. Elwesii) from Argentina. The same author (Curtis' Bot. Mag. pi. 

 s 553- 1914) describes and illustrates a new species of Zephyranthes (Z. cardi- 

 nalis) from specimens growing in the Kew Gardens but presumably of Ameri- 

 can origin.— J. M. Greenman. 



Root nodules. — Bottomley 3 has investigated the root nodules of Ccano- 

 tkus america nus, to which attention was called by Beal in 1890. He finds that 



formation of endogenous outgrowths similar in structure to the primary branch. 

 Each nodule when fully grown shows an apical meristematic zone, an infection 

 zone, a bacterial zone, and a basal zone almost free from bacteria. The 

 bacteria when isolated and grown in pure cultures can fix free nitrogen, and 

 evidently belong to the Bacillus radicicola group. 



Miss Spratt 6 has studied the well known root nodules or "coralline roots" 

 of the cycads, and finds that all the genera produce them. They are developed 

 primarily by infection with Bacillus radkhola. and at the base of each nodule 

 a whorl of lenticels or a continuous zone of parenchyma is produced. The 

 outer cell walls become pushed apart, and are infected by Azotobacter, and under 

 certain conditions by Anabaena also. The alga is said to stimulate the phel- 

 logen to produce other lenticels, from which a zone of tissue is produced that 

 includes the original outer cells in which the alga and bacteria occur. The algal 

 zone is continuous, and consists of a large air space containing Anabaena and 

 Azotobacter, which is kept intact by papillate cells traversing it from both inner 



