14 BULLETIN 581, U. S. DEPARTMENT OF AGRICULTURE. 
between, rot and count under factory conditions, 20 per cent of rot. 
was the highest on which the full data were secured. From 0 to $ 
per cent of rot the mold count rises sharply. Beyond 4 per cent the 
rate of rise gradually decreases, until after 20 per cent of rot the rate 
of increase is slow. On the whole, the zone was higher on factory 2 
than on laboratory samples. The chart shows that a count of 60 
per cent molds represents a rot content of not less than about 4 per 
cent. It is interesting to note that the mold count of 25, which was 
suggested as a factory working basis in 1911, represents at least 0.8 
to 0.9 per cent of rot. There may be more rot than that present, 
but, on the basis of the data at hand, it is highly improbable that it 
represents less than that amount. From the chart it is possible to 
calculate the approximate minimum percentage of decay represented 
by a given mold count. Thus, for instance, a mold count of 40 enters. 
the “‘Zone of Possible Mold Counts” at a point representing 2.2 per 
cent of decay. Therefore a count of 40 may be obtained in samples 
having any amount of rot between 2.2 and 100 per cent. 
SPORE AND YEAST COUNTS. 
As has been pointed out, such a degree of efficiency in washing and 
sorting may be maintained in good factory practice that the percent- 
age of decay in stock will be 1 per cent or less. With this in mind, an 
examination of Tables 7 and 8 shows that on samples contaming such 
amounts of objectionable material the counts on yeasts and spores 
are 20 or less per 1/60 cmm. In the majority of the samples the com- 
paratively low numbers of this type of organisms are noteworthy. 
This fact serves to emphasize what has already been stated, that high 
counts of these organisms are more frequently an indication of sec- 
ondary than of primary spoilage. Thus in the factory series of sam- 
ples (Table 8), which includes those having large amounts of decay, 
only one sample high in these organisms is found. In this case 
(Sample 39) it was trimming stock and was not made up as promptly 
as it should have been; consequently a certai amount of secondary 
spoilage had occurred. The estimate of 20 per cent rot is therefore 
under rather than over the true amount. All of the other factory 
samples were handled in such a way as to prevent appreciable sec- 
ondary spoilage. 
The combined results of yeast and spore counts, both on laboratory 
(Table 7) and factory tests (Table 8), have been plotted in Figure 3. 
Here it is seen that up to a count of 10 the results may be regarded 
as negligible. A count of 20 represents about 1 per cent of decay. 
From this point the rate of increase is slower. As in the case of 
molds, the rule that a moderately low yeast and spore count may 
not always indicate good stock but does indicate at least a certam 
amount of rot, holds good for this class of organisms. It is also 
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