

FUNGI IN CHEESE RIPENING. IOI 
VITALITY OF- SPORES: 
Studies have been made upon the vitality of the spores of the 
species used. This varies greatly in different species. In 
some of the most common forms spores have been reputed to 
remain viable for several years. Recent studies by Wehmer 
showed that five species of Penicillium used in his experiment 
were entirely dead in laboratory cultures at the end of two and 
one-half years. Cultures of the Camembert Penicillium grown 
upon potato in test tubes plugged with cotton have refused 
entirely to germinate at the age of one year. Other cultures 
have seemed entirely dead inside of six months. In fact the 
spores of this mold are very thin-walled and lose in percentage 
of viability very rapidly when stored. Under such conditions 
they lose turgidity and become crenulated or indented. Spores 
of Monilia candida and several others have grown after more 
than a year in laboratory cultures, but their germination was 
much retarded. Oidium lactis seems to be very easily killed 
by drying as would be expected from a species with such thin- 
walled spores. The Roquefort Penicillium under some condi- 
tions is more resistant but loses vitality quite rapidly. It is 
certain therefore that material for inoculation should be fresh 
and vigorous to give the best results. Under ordinary circum- 
stances it would not be desirable to attempt to use material 
more than a few weeks old. 
CONTAMINATIONS. 
The number of molds found upon market Camembert cheese 
shows the need of care in guarding against contamination of 
cultures. Hxtraneous molds may come (1) from the milk (2) 
or from the utensils used, (3) from the clothes and hands of the 
workmen. Although the milk is the primary source of most 
infections, practical experiments have shown that if the proper 
molds are put upon the cheese at the time of making the 
troubles arising in this way may be minimized. In fact, suff- 
cient contamination from this source directly to ruin a cheese 
is very uncommon. 
The very habit in some countries of washing or rinsing cheese 
making utensils in whey will account readily for the universal 
presence of Oidium lactis and perhaps for many of the bacterial 
infections that result in loss. But the source of the most 
