BY R. GREIG SMITH. 171 



Linseed mucilage is derived not from one microbe but from many. 

 I may be wrong in my belief, and one bacterium may indeed be 

 responsible. If so, then organism " a " or " b " may be the 

 active microbe. On the other hand, the true producer may not 

 have been isolated. 



From the research the following conclusions may be sum- 

 marised : — 



1. The gums of Linseed mucilages vary in their chemical 

 reactions, and therefore probably vary in their chemical constitu- 

 tion. 



2. The product of hydrolysis consists of galactose and reducing 

 substances which yield indefinite osazones and which are possibly 

 akin to the furfuroids of Cross, Bevan and Smith. 



3. The gum bacteria in the tissues of Linum are relatively 

 very numerous, and consist chiefly of races of two species. 



4. The chemical reactions of the gums from these are practically 

 identical with the reactions of Linseed gum. 



5. The gum of one of the bacteria is hydrolysed to galactose, 

 and of the other to galactose and a reducing substance that yields 

 an indefinite osazone. Both gums contain a large proportion of 

 the furfuroid substances. 



6. The gum, formed b}^ bacteria, is probably altered by the 

 plant into mucilage and other substances required in the plant 

 economy. 



7. A number of so-called species of gum bacteria have probably 

 one common origin; the host plant can alter the nature of the 

 gum product which influences the growth-characters. 



Bacillus lini i., n.sp. (Organism "a.") 



Shape, etc. — The bacterium appears as a motile short rod, 

 negative to the Gram stain. On nutrient agar, the cells are thin 

 and measure 0*3 : 0-6-1 -5 /u, the average being 0*3:1/li. On 

 saccharose-potato-agar, the cells were stouter and measured 

 0-5 : 0-8-1 -2 /x, the average being 0-5 : 1 /x. In bouillon, they 

 appeared as a mixture of the thin and thick forms. The flagella 

 are numerous and peritrichous; up to five have been observed. 



