286 



nograms is quite changed when compared with the original state, 

 for by their intense increase the o|)a((ne bacteria produce an also 

 opaque auxanogram, whilst the original slime was transparent like 

 glass. This proves that, in this case at least, the biological function 

 of the slime is that of a reserve food. 



In this experiment cane sugar was the food for the slime pro- 

 duction; as hereby inveision lakes place, glucose and levulose are 

 probably the building materials of the slime; that these sugars are 

 assimilated was stated above, and that glucose may also serve for 

 the described experiment we ascertained particulai-ly. 



The other sugars have not yet been extensively examined from 

 this point of view, but it seems that all give the same result. This 

 leads to the conclusion that probably no more than two or three 

 factors or genes (endoenzymes) are active in the production of the 

 cell-wall. The problem is evidently of theoretic interest and deserves 

 nearer reseaich. 



The wall-substance, which certainly belongs to the cellulose group 

 and therefore may be called cellulan, must have a high power of 

 attraction for water, foi- else its surprising volume cannot be explained. 

 Nevertheless its molecules cannot be very small as they cannot diffuse 

 at all in water. It is not colored by jodine, nor is it attacked by 

 diastase. But as B. polymyxa may use it as a food-substance, this 

 species evidently can exci-ete an enzyme which dissolves it. It is 

 not improbable that this enzyme is pectinase, but this question is 

 not yet answered. Should this really prove to be true, then the other 

 question arises whether the so-called pectose of the central lamellum 

 of the tissues of the higher plants may not also be a cellulose 

 modification, as \t is also easily dissolved by pectinase. This view 

 seems to be much more acceptable than the current hypothesis : 

 the central lamellum should be the calcium salt of an acid, isomeric 

 with arabin-acid. 



On the great similarity between pectinase and the seminase of 

 the seeds of the Leguminosae, I already earlier directed the atten- 

 tion. That the latter enzyme does not attack true cellulose is in 

 accordance with the same property of pectinase. 



SUMMARY. 



With a not too limited species-conception Clostridium polymyxa, 

 Granulobacter polymyxa, Bacillus macerans, and Bacillus asterosporus 

 may be brought to one single species : Bacillus polymyxa. 



It is the otily hitherto known aerobic spore-former, which, in 



