THE CAMEMBERT TYPE OF SOFT CHEESE. 63 
development. During that time it seems to be so thoroughly 
adapted to thrive upon cheese as to exclude almost every other 
form, but after its cycle of development is complete, it may be 
followed by other species which, if present before, are held in 
check by the more vigorous species. 
One more phase of the mold problem perhaps belongs in this 
preliminary paper. Efforts have been made to find whether it 
is possible to substitute other varieties or species of the same 
genus of fungi for the one we have been using. For such 
studies the mold of Roquefort cheese has been carried as a check 
upon our work in numerous experiments. One other variety 
of Penicillium differing only in that it never changes color, but 
remains pure white, has been tested. Cheeses have been made 
with these three and several other related'species. The Roque- 
fort Penicillium grows strongly and rapidly upon cheese but its 
presence always causes a bitter taste which remains pronounced 
during the period of four or five weeks necessary for the ripen- 
ing of Camembert. So strong is this effect that the presence 
of a colony of this mold less than an inch in diameter may often 
be detected by the taste of the cheese two inches away. The 
pure white Penicillium in its ordinary reactions to culture media 
seems to be identical with the Camembert mold, but when 
tested upon over one hundred cheeses, produced a texture so 
entirely different from the other as to make the product entirely 
worthless. It seems most surprising that two forms, so closely 
related .in structure and in every reaction studied, should pro- 
duce such different results in cheese ripening. Several other 
forms haye been tried. Some produce pigments which discolor 
the cheese. Some produce bad flavors. A set of four species 
although allowed to grow for a period of six weeks, produced 
no softening of the curd. In two of these cheeses especially 
it was found that the curd was still sour and little changed less 
than one-fourth of an inch below the colonies of the fungus. 
The four cheeses used in this experiment belonged to a set of 
twenty, sixteen of which ripened readily in the ordinary way. 
Sets of cheeses made from the same milk and treated alike rip- 
ened quite uniformly asa rule. Of this set, sixteen ripened in 
the usual manner when acted upon by Camembert Penicillium. 
Four inoculated with other Penicillia refused to soften. Such 
a result shows that neither the molds used nor the bacteria and 
