Bacteriologie. — Bryophyten. 293 



accelerate, depress or prevent gum-formation. Traces of alkaline 

 citrate or succinate were most favourable, Sumach tannin assists the 

 formation of gum upon artificial agar media. Oak tannin hinders 

 the formation, but the retarding effect may be neutralised by the 

 addition of glycerine. The bacterium might be used to distinguish 

 certain tannins. The tannin probably acts physically by making the 

 medium more contractile, so that the bacteria are slowly supplied 

 with nutrients Solution. The Optimum temperature is 17° C. The 

 most suitable medium, as deduced from the experiments, serves as 

 a diagnostic for other gum bacteria. Gum acacia has not a cellulose 

 origin. In the host plant it is formed from the wandering sugars, 

 levulose and maitose. Manuring with saline matters does not promise 

 to be a remedy for the prevention of gum-flux in fruit trees. Peach 

 trees that were' inoculated with Bact. acaciae (from Acacia bhiervata) 

 developed gum-flux. The exudate was a metarabin gum. The host 

 plant can convert Bact. acaciae into Bact. metarahinum, proving 

 what had been suspected, that the latter is a variety of the former, 

 producing an insolube gum. This explains the uniformity of the 

 gums from certain species of trees. Smith. 



Smith, R. Greig. The Red String of the Sugar-cane. (Abstr. 

 Proc. linn. Soc. N. S. Wales. 1904.) 



Instances of the vascular strings of the sugar-cane being coloured 

 a deep red from the presence of a red gum in the large vessels 

 have been recorded in connection with certain diseases, such as 

 Sereh, the Sugar-cane Disease of Massee, the Pineapple Disease of 

 the Cane, and Red Smut (Red Rot), in all of which it has been 

 denied that bacteria produce the gum. The cases of red string 

 investigated by the author occurred in apparently healthy plants, 

 and also in canes affected with gummosis. The gum was produced 

 by Bacillus pseudarahimis , n.sp., and the crimson colour was 

 imparted to it by a mould. The co-existence of the two is essential 

 for the production of the colour in the vessels of the sugar-cane. 

 Both organism are described in detail. The gum gave the reactions 

 for arabin, but as it hydrolysed to galactose only it was a galactan. 



Smith. 



Bpotherus, V. F., Contribution ä la flore bryologique de la 

 Nouvelle Caledonie. (Öfversigt of Finska Vetenskaps-Socie- 

 teters förhandlingar. N'J. 15. 28 pp. Mit einer Tafel. 1905—1906.) 



Bisher waren 157 Laubmoosformen, Arten und Varietäten, von 

 welchen 105 Formen im Gebiete endemisch sind, von Neu-Cale- 

 donien bekannt. Durch die Bearbeitung, welcher Verf. die Moossamm- 

 lungen, die von den Herren M. Bernier, M. M. Etesse und 

 Le Rat in der Insel gemacht wurden, unterworfen hat wird die Moos- 

 flora derselben mit 55 Arten bereichert. 



Vom Verf. wird eine neue Gattung Parisia mit der neuen Art 

 P. neocaledonica aufgestellt und beschrieben; diese Gattung wird 

 zwischen Campylopiis und Synodontia in der Familie Dicranaceae 

 gestellt und zeichnet sich besonders durch die nervenlosen und 

 mit einem langen Haare versehenen Blätter aus. 



Folgende neue Arten werden von dem Verf. und Herrn General 

 Paris beschrieben: 



