( 478 ) 



Pectine, prepared as indicated § 2, is decomposed, as well with 

 aliinmine, peptone, or broth, as with ammoniiimsalts for source 

 of nitrogen, by which this bacterium stands by itself and is sharply 

 distinguished, especially from the butyric-acid and the butylic fer- 

 ments, which do not attack pectine at all. When the pectosc is 

 attacked, pectosinase secretion occurs. 



Cellulose as filter-paper, is not in the least alfected by G. pec- 

 tlnovorum. Hence, the flax-fibre as such remains quite unchanged in 

 the rotting, but the less resistant forms of cellulose are solved quite 

 as the pectose itself. Gum arabic remains intact. As is seen from the 

 photogram (Plate Fig. 2), the image of the pure culture on malt- 

 extract agar is quite different from that of the butyric-acid ferment, 

 which latter forms thick Clostridia. 



This difference is not less clear in the culture liquids. Thus, in fig. 4 

 we see the form of the bacterium in a pectine fermentation at 35" C. in : 

 Tap-water 100, Pectine 2, (NH')^ SO^ 0,05, KUiPO^ 0,05, Chalk 2. 



The dark portions represent the places where granulose is accu- 

 mulated. Clostridia of the common form are completely absent. The 

 shape of our bacterium in this or such like culture liquids is charac- 

 teristic, and is not found in any other species except 6^. ?{roct?/;Ari/»//?. 



11. Description of Grariuhhacter urocephalum. 



The difïerence between G. pectinororum {Gp F. 2, Plate Fig. 3) 

 and G. urocepkalum {Gu Fig. 2 Plate Fig. 4) which likewise, albeit 

 in smaller number, accumulates in the rotting flax, consists first in 

 the shape, wdiich for the latter more approaches the "drumstick 

 form", although the spores are not round, but oval, as Fig. 2 § 3 

 shows with great distinctness. Further, in the former secreting a 

 much larger quantity of the rotting-enzyme pectosinase, which is the 

 very reason why G. pectinovorum is more common in rotting flax 

 than (r. urocephaJini) . 



Both species produce much mucus, which consists of the thickened 

 and liquefied cell-walls of the bacteria themselves, and is found back 

 in the so-called rotting-gum, obtained by evaporation to dryness of 

 the rotting-water. That this species also stains deep blue with iodine 

 is suggested by the generic name. 



A characteristic difference between the two species is the following. 



The colonies of G. pectinovorum (PI. Fig. 3), when kept on plates 

 of dilute malt extract agar with chalk, will relatively promptly be 

 decomposed into a detritus, wdierein only the spores can clearly 

 be recognised, whereas the colonies of G. urocepkalum (PI. Fig. 4) 



