168 BACTERIA IN RELATION TO PLANT DISEASES. 
BACTERIA WITH FUNGI. 
In 1903, Zederbauer published a paper on the Myxobacteriaceae, in which he claims 
that he has demonstrated that certain of these organisms are a symbiotic combination of 
bacteria and fungi. 
His first investigations were made on a reddish form, which he calls Myxococcus incrustans, 
growing on sponges used for wetting gummed paper. This form, which looked like a slime mold 
was made up of bacteria, chiefly, with occasional fungous hyphe, and chains of small round bodies 
which he thinks were conidia. 
He succeeded in obtaining pure cultures of the bacteria (some of them, at least) on peptone 
gelatin. At room-temperature, in the light, they grew rapidly, forming a film of branching radiating 
chains of bacteria on the surface. In rather old colonies these floated for a time on the liquefied 
gelatin, then sank to the bottom. Growth occurred also below the surface, but was not so luxuriant. 
All cultures, in repeated experiments, produced the same bacterium. The color of the 
Myxococcus is not shared by the bacteria. The colonies are dirty white. Spores were formed in old 
cultures. No cilia were demonstrated, nor was the movement like that of ciliated forms. On agar, 
growth appeared similar to that on gelatin, but the agar was not liquefied. The bacteria did not 
grow on sterilized bread or potato. 
The fungus was also cultivated separately. Spores taken from the so-called Myxococcus ger- 
minated in the usual manner, forming several celled hyphe, which soon produced conidia, like the 
original spores. Mycelium also developed from oidia which were formed by the breaking up of 
filaments. 
Although Zederbauer thus cultivated both fungus and bacteria separately, he did not succeed 
in reproducing the original mixture, the Myxococcus, by growing them together. 
Cysts, he states, like those described by Thaxter, were found. These were composed of bacteria 
and chains of conidia surrounded by a common envelope, probably composed of hardened slime 
secreted by the bacteria. On germination, this bursts and the new organism begins growth. 
The color of his Myxococcus is not constant. It may be red, pale yellow, and sometimes black. 
A form which he calls Chondromyces glomeratus was found in several localities growing in groups 
upon the cut surface of beech stumps which had not begun to decay. ‘The slimy red outgrowths 4 to 
5 mm. high, resemble Tremella. This form he says was also composed of bacteria and fungoushyphe. 
The long slender hypha, rising from spores at the base, intertwined and formed at the surface a 
thicker layer of conidiophores bearing chains of conidia. The very small rod-like bacteria which 
swarmed in the interior were actively motile. 
Several conidia were germinated in a moist room, forming hyphz, which, however, did not 
produce conidiophores. 
The bacteria, which stained with methylene blue and fuchsin, grew on gelatin and agar. On 
gelatin plate cultures at room temperature or in the thermostat at 20°C., small dirty white drops 
were formed which united and liquefied the gelatin in hollows. In cultures kept near the window, 
growth was strongest near the light. Streak cultures behaved very much like plate cultures. The 
bacteria did not liquefy agar but formed over the whole surface a dirty white layer, starting from 
small round flecks. All cultures were fluorescent. 
The flagella, attached to all parts of the body, were stained with Van Ermengem’s stain as modi- 
fied by Hinterberger. In some cases they were ten times the length of the bacteria. Spore formation 
was not observed. 
In gelatin cultures when hyphe were brought in at the point of inoculation they took on irre- 
gular shapes and seemed to form conidia. Chlamydospores were also formed in such cultures. 
Zederbauer claims that the origin of these demonstrates that they are fungous spores and not 
bacteria as claimed by Thaxter. 
The first part of this paper is devoted to speculations on whether Thaxter’s statements and 
figures can be interpreted as indicating the presence of mycelium in the Myxobacteriaceae. There 
seem to be a good many uncertainties connected with his own researches. 
Dr. Thaxter’s comment on this paper is as follows: 
“This treatment of the group, though novel, seems somewhat hasty; especially in view of the 
fact that the figures and descriptions given in this paper show very clearly that its author is as yet 
unacquainted with any mentber of the order he discusses, having been misled by fancied resemblances 
and influenced no doubt by an exaggerated notion of the difficulties associated with the differentia- 
tion of rod-like bacteria from Oedocephalum, Torula, and similar hyphomycetous types. A specimen 
