200 SCIENCE PROGRESS 



tion by Bailey {Ann. Bot.). The hypothesis brought forward 

 by Eriksson for the persistence of this disease as naked proto- 

 plasm within the cells of the host was largely based on the 

 recurrence of the disease year after year, although he found 

 no trace of mycelium either in the seeds or young plants. 

 Bailey finds that the two types of germination of the teleuto- 

 spore are dependent on external conditions, and not on dimor- 

 phism of the spores. Two experiments were carried out : in 

 the first sterihsed seeds from diseased plants were sown in 

 conditions which prevented all infection except from internal 

 mycoplasm, whilst the controls were exposed to infection. 

 No rust appeared on any of the protected plants, whilst the 

 controls were infected. The second series of experiments, 

 lasting over ten months, likewise supported the view that 

 infection was not due to persistent mycoplasm. 



Bristol contributes a review of the Genus Chlorochytrium 

 to the Jour. Linn. Soc. in which thirteen species are recognised, 

 including those formerly placed in the genera Chlorocystis, 

 Stomatochytrium, Endosphcera, Scotinosphcera, and Centro- 

 sphcera. 



Taxonomy. — In the Journal of Botany, Baker and Salmon 

 deal with some of the segregates of Erodiiim cicutarium and 

 describe E. neglectum. A revised arrangement of British Roses 

 is compiled by Wooley-Dod. In the same journal, T. and 

 T. A. Stevenson describe a British Orchis allied to 0. incarnata 

 under the name of O. purpurella, and Lad brook describes a 

 new species of Couponi. 



The Hawaiian species of Plantago are dealt with by Rock 

 {Amer. Jour. Bot.), of which two are endemic, viz. the shrubby 

 P. princeps and P. pachyphylla. Of both these a number of 

 varieties and formae are recognised. 



An extensive paper on Mesembryanthemum by Brown is 

 contributed to Jour. Linn. Soc, and contains diagnoses of 

 more than fifty new species. 



PLANT PHYSIOLOGY. By R. C. Knight, D.Sc, Imperial College 

 of Science and Teclinology, London. (Plant Physiology Committee.) 



Storage and Translocation. — The storage of reserve food materials 

 in plants presents a diffuse problem, which by virtue of its 

 widespread ramifications can hardly be considered alone. At 

 the outset one is confronted with the fact that storage involves 

 two processes of translocation, the first by which the nutritive 

 materials are conveyed from the manufacturing tissues to the 

 storage region, and the second, following the rest period, by 

 which the store is transferred to the growing organs. Thus, 

 in addition to the actual process of accumulation of the pro- 

 ducts of assimilation in stem, root, or fruit, we have to con- 



