ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 353 



found that gum drops oozing from the seed capsules and twigs of 

 StercuUa diversifolia consisted of a mixture of arabin and pararabin. 

 The arabin is produced by Bad. acacice. Another organism — Bad. 

 pararaUnum, sp. n. — was isolated from the gummed fruits, etc. Upon 

 solid media and in solutions containing saccharose, dextrose, levulose, 

 galactose, mannite or glycerin, a slime is formed. By appropriate treat- 

 ment this yields a soluble pararabin gum, which upon dehydration 

 becomes insoluble, and this modification is soluble in dilute acid and 

 insoluble in dilute alkali. It is not hydrolysed by dilute acid, but 

 strong acid converts it into arabinose and galactose. The bacterium 

 does not secrete invertase, and in solution of saccharose it forms gum, 

 ethyl-alcohol, carbon dioxide, succinic, lauric, acetic, butyric and 

 formic acids. 



