May 1, 1930 



Spores of Bacillus Larvae in Honey 



701 



cubic centimeter (table 2). This difference, which is relatively 

 constant for each sample, may be due to the fact that some spores 

 are lost during the centrifuging, but more probably to the fact that 

 a certain proportion of the spores in each smear are covered up and 

 not seen in the masses of stained debris always present even in honey 

 of the highest quality. 



DETERMINATION OF ACCURACY OF THE METHOD 



STATISTICAL ANALYSIS OP THE DATA 



Since the data obtained for the actual mean number of spores per 

 field (table 1) for each honey-spore sample, if plotted against the data 

 calculated for the theoretical mean number of spores per field (table 

 2), give practically a straight line having a trend similar to that of 

 a line plotted for the theoretical data alone, the relation between the 

 theoretical means and the actual means, for the five honey-spore 

 samples used, was determined by the customary statistical methods. 



The standard deviation and the probable error for the actual mean 

 number of spores per field were determined from frequency tables 

 prepared from the original data (table 1) for each honey-spore 

 sample used '° (table 2). The actual means were derived from large 

 samples (60 fields each), and the calculated probable errors and 

 standard deviations were shown statistically to be small. 



The coefficient of correlation " between the values for the actual 

 mean number and those for the theoretical mean number of spores 

 per field for each sample as given in table 2 was found to be 0.9999 ± 

 0.0001. 



The relation between the actual mean number of spores per field 

 recovered from each honey-spore sample and the corresponding most 

 probable values estimated from the theoretical mean number of spores 

 per field for each sample was determined by use of the regression 

 equation for the actual mean number of spores. This was found to 

 be r=0.8905-X'— 0.1791. Substituting the various values of the 

 theoretical mean number of spores per field (table 2) for X in this 

 equation gave the most probable estimated values for the actual mean 

 number of spores per field (Y) that should have been recovered from 

 each sample (table 3). These most probable estimated values were 

 found to be in excellent agreement with the actual values obtained. 



Table 3. — Theoretical and actual mean numbers of spores per field and the most 

 probable estimated theoretical and actual mean numbers of spores per field 



" Chaddoce, B. E. PEINCIPLE3 AND METHODS OF STATisTica. pp. 160-164, 240-241. Boston, New 

 York [etc.]. 1926. 

 " Oboxton, F. E., and Cowden, D. J. practical bdsiness statistics, p. 416. New York. 1934. 



