192 Report oF DEPARTMENT OF BACTERIOLOGY OF THE 
of the cellulose layers, removing only the middle lamella, and 
also left the starch grains intact. 
Wehmer (1898) studied the bacteria concerned with the rot- 
ting of potatoes, all of which he regarded as of saprophytic 
nature. He found two types of decomposition to occur, asso- — 
ciated with different organisms. In the first, “ breifaule,” the 
middle lamellae only are dissolved. He considers that the acid © 
produced by bacteria may be the agent in this solution of 
the pectic componds, rather than an enzym. In the second, 
“ schleimfaule,” there is ultimately solution or the entire wall 
substance. 
Laurent (1899) working with Bacillus coli communis found 
that, although normally a saphrophyte as concerns plant tis- 
sues, yet when inoculated into weakened vegetables it developed 
there and in so doing acquired virulence as a parasite upon 
potatoes of full vigor, and also upon turnip and onion. There 
was no secretion of diastase (amylase). Heating the culture 
to 62° C. for five minutes destroyed this ferment. 
Lepoutre (1902), continuing Laurent’s work by similar 
methods, developed strains pathogenic to plant tissues of three 
other species of bacteria, normally saprophytic, viz., Bacillus 
fluorescens liquefaciens, B. mycoides and B. mesentericus. The 
first acted like B. coli communis in Laurent’s cultures, viz., 
dissolved the middle lamella, but not the cellulose or the 
starch. Lepoutre considered the solution of the lamella due 
to an enzym which he speaks of as a variety of pectinase, 
evidently accepting the name suggested by Bourquelot and 
Herissey (see discussion later in this paper). 
Migula (1900:529) states that the culture of his Bacillus 
asterosporus upon slices of cooked carrot leads to the solution 
of the middle lamella. 
Winogradsky (1895) studied the retting process of flax and | 
considered it due to a single specific anaerobic bacillus. He 
concluded that this fermented the pectin elements readily but _ 
was without influence on cellulose proper, e. g., Swedish filter 
paper. This conclusion is in accord with the opinion expressed 
by Kolb (1868) that the retting process is essentially a pectic 
fermentation. 
