1285 
be elementary, will not, on continued examination, prove to be 
composed of other still unknown factors. 
As to dextran I have stated elsewhere ') that it isa wall substance 
comparable to levulan, likewise only resulting from cane-sugar, but 
produced by some lactic acid ferments, belonging to the physiological 
genus Lactococcus. Dextran, however, never originates independently 
from the cell, as may occur with levulan, but exclusively at the 
surface of the outer layer of the protoplasm and in direct contact 
with it. But the knowledge of the relation between levulan and its 
producing enzyme, viscosaccharase, indicates clearly that dextran, 
whose properties are so analogous to those of levulan, must have a 
similar origin. It is therefore most probable that dextran also arises 
under the influence of one single factor or specific enzyme, which 
might be called saccharo-dextranase, but which, being an endoenzyme, 
cannot leave the cell. 
The formation of the slime wall by B. prodigiosum viscosum *) 
must be brought about by at least two factors, differing from 
levulanase and dextranase since the slime produced by this bacterium, 
belongs to the celluloses or cellulan-slimes. That beside the slime 
factor, which might be called cellulanase and which produces cellulan 
from carbohydrates, still quite another factor operates here is proved by 
the following observations. By feeding this bacterium with glucose, cane- 
sugar, maltose or lactose, wall slime is readily yielded. In several 
other species, for instance Aerobacter viscosus and Bacillus polymyaa 
we find the same. But B. prodigiosum can besides produce slime 
from albuminous substances such as gelatin and peptone, which B. 
polymyxa and A. viscosus cannot. As now it is quite unacceptable that 
one and the same factor could be able to produce cellulose slime as 
well from proteids as from carbohydrates, B. prodigiosum must 
possess a specifie factor able to split off from the albuminous matter 
an enzyme-substrate, converted into cellulose slime by the wall- 
forming factor. But this proteid-splitting factor does not exist in 
B. polymyxa and A. viscosum. B. prodigiosum viscosum is thus a 
mutant, distinct by at least two factors from B. prodigivsuin itself, 
which produces no slime at all, neither from carbohydrates nor from 
proteids. It must thus be possible to detect another still unknown 
mutant lacking the factor to produce from proteids a substrate that 
1) Die durch Bakterien aus Rohrzucker erzeugten Wandstoffe. Folia microbiolo- 
gica. Bd. 1. Page 392, 1912. 
*) B. prodigiosum viscosum is no natural form but a mutant or race, easily 
obtained from B. prodigiosum. Folia microbiologica, Bd. 1, Pag. 35, 1912. 
82* 
