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18 The Botanical Gazette. {January, 
of forceps reddened in the flame, upon the sterilized glass 
slide, so that one end came in contact with the weft or 
strand of the Ozonzum. 
At the same time similar sections of sterilized cotton roots 
were placed in test tubes and partly imbedded in moist sand 
or partly immersed in distilled water, the tubes with their 
contents afterwards being thoroughly steam sterilized. 
In from twenty-four to forty-eight hours the Ozenium 
strands would bite hold of the bait placed before them and 
secure such firm hold that the section of root could be trans- 
ferred bodily to the prepared culture tubes, placing the end 
containing the growth in contact with the sterilized root al- 
ready in the tube. Sterilized sweet potatoes were also used 
in test tubes as a medium upon which to place the trans- 
plantings. 
Since the fungus grew rather slowly, and there was always 
danger that it might be contaminated by other fungus threads — 
which had crept along with it, or with bacteria, some thirty 
or forty moist chambers during a period of six weeks were : 
used, and more than 200 baits were set for the fungus. Out 
of this number seventy-five baits, which were promising, were 
transferred to roots in the culture tubes, and from these four 
or five finally proved to be pure. From these, baits could — 
now be easily handled, so that in the course of two weeks I 
had multiplied the cultures to the number of fifty. 
Great difficulty was encountered in baiting in such a way 
as to avoid contamination from strands and wefts of Gdoceph- 
alum, several species of Fusarium, Penicillium, Mucor and ~ 
some non-fruiting forms, which also grew out from the roots 4 
and crept over the filter paper. In several cases bacteria — 
were starved out by making the medium slightly acid with — 
the use of lactic acid. 
The Ozonium on artificial media, as sterilized cotton roots 4 
NE swree potatoes, grows readily after once obtaining a firm — 
old, and possesses all the characteristics observable in 2 — 
natural condition upon cotton roots. Being free from ob- 
structions and hindrances which it encounters in nature, the - 
growth is perhaps much more compact, numerous strands — 
uniting to form a broad weft, but the peculiar strands are — 
mee as well as the characteristic branching sete. 
n the first transplantings the fungus grew with difficulty, 
since I did not have the conditions perfect, but as with expe-_ 
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