650 Palaeontologie. — Pflanzenkrankheiten. 



drift that is presumabry tertiary. The tree seems to be one of the 

 Abietineae. M. C. Stopes. 



Stopes, M. C, Further Observations on the Fossil Flower. 

 (Rept. Brit. Assoc. Adv. Sei. p. 783. Scheffield 1910.) 



Abstract of paper read at the association meeting giving further 

 particulars about the petrified flower Cretovarium japonicum Stopes 

 and Fujii from a new speeimen that shows the fleshy laj^er of the 

 ovary walls and contains ovules. M. C. Stopes. 



Stopes, M. C, The 'Dragon-tree' of the Kentish Rag, with 

 Remarks on the treatment of Imperfectiy Petrified 

 Woods. (Geol. Mag. VIII. 560. p. 55-59. textfig. 1911.) 



The "Dragontree", described since 1862 variously as a Monoco- 

 tyledon of various kinds, or as a Cycad, is shown to be merely the 

 remains of an Abietineous trank in a very poor State of preservation. 

 The supposed external features of the supposed genus are shown 

 to be not really characteristic. The only real feature retained in the 

 fossil are small fragments of pulverising wood which had hitherto 

 escaped Observation, and which show round bordered pits in Single 

 rows. The speeimens have consequently no claim to a distinet ge- 

 neric name though they have had several. M. C. Stopes. 



Barker, B. T. P. and G. T. Gimingham. The fungicidal ac- 

 tion of Bordeaux mixtures. (Journ. Agric. Sc. IV. 1. p. 76—94. 

 1911.) 



Various theories of the fungicidal action of Bordeaux mixture 

 are current. and these are examined by the authors. There is no 

 conclusive evidence to show that atmospheric agencies aid in the 

 conversion of the insoluble forms of copper Compounds to soluble 

 forms. It is also not proved that healthy leaves exerete substances 

 which dissolve the copper Compounds, though the exeretions from 

 injured leaves exercise a deeided solvent action. 



A historical aecount is given of work dealing with the possible 

 interaction between the tungus on the host plant and the insoluble 

 Bordeaux preeipitate, direct action between the two being indica- 

 ted. Further experiments with various fungi were undertaken to 

 test the truth of this hypothesis, and it seems certain that this direct 

 action of the fungus upon the preeipitate does oeeur, but it is purely 

 local in distribution , actual contact between the insoluble copper 

 particles and the fungus being necessar}' - to cause the death of 

 the latter. 



It is probable that the fungicidal effect of Bordeaux mixture 

 is not only due to the toxic action on the fungus, but also to 

 an indirect protective action on the foliage, rendering it more or 

 less immune from subsequent infection. The latter action is gene- 

 rally regarded as the most important. W. E. Brenchley. 



Essed, Ed., The Surinam disease. A condition of Elephan- 

 tiasis of the Banana caused bv UstilaginoideUa oedipigera. 

 (Ann. Bot. XXV. p. 363—365. 1911.) 



The disease appears as an enormous distension of the base of 



