Bacteriologie. 173 



metarabin. The formation of arabin and metarabin by the bacteria 

 was confirmed. 



V. The Gum-flux of the Plum. 



The natural gum consisted of arabin and metarabin. From the 

 soft gum of a rather old specimen Bact. acacim was obtained , showing 

 that the gum-flux is caused, in part at least, by this bacterium. 



VI. The Gmn-fliix of the Cedur. 



Small amber-coloured „tears" of gum were associated with the 

 presence of Bnct. acacice, and possibly another organism, Bact.. 

 persiccE, n.sp., which will be subsequently described. 



VII. The Gum-ßux of the Peach. 



The gum exuding from the fruit consists of dead bacteria in a 

 gum matrix. The gum is formed in the stem and branches, in part 

 at least, by Bact. acacice, and with it is associated Bact. persicce. 



VIII. The Gum-ßux of the Ahnond. ' 



Is identical with the gum-flux of the peach. Bact. acacice is the 

 Chief gum-former. 



IX. The Gum-flux of an unknowii Stock of the Japanese 



Date Plum. 



Bact. acacice is chiefly responsible for the exudation. 



Smith. 



Smith, R. Greig, The Bacterial Origin of the Gums of the 

 Arabin Group. (Abstr. Proc. Linn. Soc. N. S. Wales. 1903.) 



X. The Pararabin Gum of Stercidia. 



The gum of Stercidia diversifolia consists of a mixture of arabin 

 and pararabin. The arabin is produced b}^ Bact. acacice. Another 

 organism, Bact. pararabinuni n. sp., was isolated from the gummed 

 fruits, etc. Upon solid media and in Solutions containing Saccharose, 

 dextrose, levulose, galactose, mannite or glycerine, a slime was 

 formed. By appropriate treatment this yielded a pararabin gum 

 which was soluble in dilute acids and insoluble in dilute alkalies. 

 It was not hydrolysed by boiling 5 ^/^ sulphuric acid , but by treat- 

 ment with concentrated sulphuric acid the carbohydrate was con- 

 verted into arabinose and galactose. The bacterium did not secrete 

 invertase, and in Solutions of Saccharose formed carbon dioxide, 

 ethyl alcohol, succinic, acetic, butyric and formic acids. 



Smith. 



Smith, R. Greig, The Gum and Byproducts of Bacterium 

 sacchari. (Abstr. Proc. Linn. S^c. N. S. Wales. 1903.)j 



The gum has been identified as a galactan. The byproducts in 

 the fermentation of Saccharose are 'carbon dioxide, ethj^l alcohol, 

 succinic, lauric, palmitic, acetic and formic acids. Smith. 



Smith, R. Greig, The Gummosis of the Sugar Cane. (Abstr. 

 Proc. Linn. Soc. N. S. Wales. 1902.) 



From the gum of diseased stalks Bacterium vascidarum , Cobb. 



