Counting of Borrelia duttonii Using Counting Slides and the Dark Field Microscope of Completely Dry System

The availability of the counting slides devised by Yoshii and by Tawaraguchi was studied using the dark field illumination recommended by Yoshii. The test organism used was Borrelia duttonii. Each of all slides was of Thoma-haemocytometer type and less 2mm. in thicknes. The Yoshii's slide consisted of two types. The depth of the counting chamber of one type was 0.020mm. and that of other was 0.010mm The Tawaeaguchi's slide had 0.010mm. depth chambers. The results obtained were treated statistically and could be summarized as follows : 1) There was no evidence that the distribution of borreliaa in any chamber of three types differed significantly from the Poisson distribution. 2) There was no evidence that the sample estimate of mean of 50 replicate counts in these types of chambers differed significantly from one another. 3) The depath of chambers was concluded to excert an influence upon the precision. The value of the coefficent of variation obtained was 9.97, 14.97 and 18.42 by use of 0.100mm-, 0.020mm- and 0.010mm-slide respectively. 4) The numbers of counts needed to obtain the mean with the error less than 0.10 at the 95% fiducial limits was estimated as 4 or more in the 0.100mm-slide, 9 or more in the 0.020.mm-slide and 14 or more in the 0.010mm-slide respectively.