524 FOOD PRESERVATION 
bacteria per cubic centimeter. In calculating the bacteria, it is observed 
that there are 400(20 20) small squares on the slide. The number of 
bacteria in rectangles (B, B, etc.), each containing five of these small 
squares, are counted and an average made. This average represents 
the bacteria in 1/80 of the total ruled area. Since the cell is 1/10 mm. 
deep, the volume represented by the organisms counted is 1/801/10 
or 1/800 c.mm. With the usual dilution of one part of product to two 
parts of water the actual volume in which the number of organisms is 
determined is 1/3 of 1/800 cm. or 1/2400 c.mm. or 1/2,400,000 e.c. 
Howard (1917) made a study of the relation between the number of 
yeasts and spores, mold counts, and bacteria (rods) and the amount of 
rot in the tomatoes. With regard to yeasts and spores a count of 
twenty was represented by 1 per cent decay. From this pomt the rate 
of increase was lower. <A count of thirty-five yeasts and spores indicated, 
according to Howard about 4 per cent of rot. Fig. 81 devised by How- 
ard shows the “‘ Zone of Possible Yeast and Spore Counts.” From this 
chart it is possible to determine the relation between a count and the 
per cent of rot which it represents. 
The relation between the number of bacteria and the percentage of 
rot is shown in Fig. 82. Howard thinks that below 15,000,000 little is 
indicated with regard to the amount of rot. Above this “and up to 
20 per cent of rot, the ratio of increase as shown on this chart is about 
20,000,000 for each per cent of rot.” Howard states that a low bac- 
terial count does not always indicate a sound stock but a high number 
of bacteria always indicates bad stock. 
Fig. 83, devised by Howard, shows the relation between the mold 
count and the percentage of rot. From this chart it is possible to 
calculate the percentage of decay from a mold count. The following is 
quoted from Howard. ‘ Attention should be called to the fact that 
beyond 20 per cent of rot the chart is plotted on the basis of the assump- 
tion that 100 per cent rot would give a mold count of 100 per cent of the 
fields. As a matter of fact, the mold count reaches this maximum of 
100 per cent of the fields with less than this amount of rot. In the 
study of the relation between the rot and count under factory conditions, 
20 per cent of rot was the highest on which the full data was secured. 
From 0 to $ per cent of rot the mold count rises rapidly. Beyond 
+ 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 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 that the mold count of twenty-five, which was 
