141 BACTERIA AND THE GUM OF IIAKEA, 



tose. The compound that simuLated galactosazone was much too 

 easily soluble in water and in alcohol, while the arabinosazone- 

 like body did not separate out from water with the normal ap- 

 pearance of that substance. It was difficult to say whether one 

 had to do with interlacing crystals or with a jelly, and, further, 

 the precipitate while on the filter was more gelatinous than the 

 crystalline precipitate of arabinosazone. The osazone-like bodies 

 with the low melting points (about 120°) were decomposed by 

 acetic acid. It must, therefore, be concluded that arabinose and 

 galactose are not among the products of hydrolysis, and further- 

 more that the osazones that are produced lack the definite 

 characters of the osazones of the well-known sugars. The gum 

 is hydrolysed to substances that reduce Fehling's solution, that 

 give ofi" the furfural odour during hydrolysis, but which give 

 indefinite osazones with phenylhydrazine. The latter can be 

 separated into groups which have melting points about 120°, 

 160° and 190°. But since dilute nitric acid oxidises the gum to 

 mucic acid, it must be assumed that there is present a substance 

 allied to a galactan. Possibly these indefinite bodies are akin to 

 the furfuroids which Cross, Bevan and Smith obtained from 

 straw. It is also possible that the gum is that indefinite but 

 much referred to substance, pectin. 



It was evident from the investigation of the products of 

 hydrolysis that the gum was not metarabin and that the bac- 

 terium allied to Bad. jnetarabuivm probably played no direct 

 part in its production. At the same time it must not be forgotten 

 that Bad. metarabinu77i is capable of producing a secondary 

 substance which while yielding arabinose and galactose upon 

 hydrolysis, did not give the typical reactions for arabin or dis- 

 solved metarabin, inasmuch as it gave a precipitate with barium 

 hydrate. I suggested that it was possibly a pectin body. 



Since the organism did not appear to be responsible for the 

 gum, I investigated the only other which produced a ropy solu- 

 tion in saccharose-asparagine-fluid. This grew as a thick, mottled- 

 white slime on .saccharose-potato-agar. The cells appeared as 

 rods of various lengths and breadths measuring OTo-OO : 1'6 /x 



