ERADICATION OF PULLORUM DISEASE 1931-32 



13 



handling was that on cold days the blood collectors placed the samples in their 

 inner pockets for approximately thirty minutes. The number of jellied samples 

 recorded at the time the sera were transferred to the agglutination tubes was 

 4,133 (1.53 per cent). The observations for 1931 are also shown in Table 2. 



Table 2 — Influence of Temperature Upon Incidence of Jellied Blood Samples 

 IN 1930 AND IN 1931 



The occurrence of jellying seems to be associated with the temperature at the 

 time of collection of the blood samples. It is thought that the marked reduction 

 in jellied samples in 1931 can be attributed in part to the difference in the method 

 of handling the samples on the cold days. However, the mean monthly tempera- 

 tures in Amherst in 1930 were lower than in 1931, as is shown in Table 3, and to 

 this fact part of the reduction is attributed. 



Table 3 — Influence of Mean Monthly Temperatures Upon Incidence of 

 Jellied Samples in 1930 and in 1931 



Month Mean Number Jellied Samples 



Temp. of 



° F. Samples Number Per cent 



Mearj Number Jellied Samples 



Temp. of 



° F. Samples Number Per cent 



October 48.9 102,735 1,994 1.94 



November.... 40.2 82,451 3,794 4.60 



December.... 28.1 53,674 5,098 9.50 



.53.6 112,509 1,062 0.94 

 44.1 98,379 1,702 1.73 



31.6 59,897 1,369 2.29 



Totals 238,1 



In general, it seemed that the number of jellied samples varied considerably 

 with individual blood collectors in spite of practically uniform equipment and 

 technique. The individual records of the eleven men who collected samples dur- 

 ing 1930 and 1931 were assembled and are shown in Table 4. 



During 1930, the individual blood collector percentages of jellied samples 

 ranged from 0.9 to 14.0 and in 1931 from 0.002 to 5.36. The records of the 

 blood collectors, with one exception, showed marked decreases in the percentages 

 of jellied samples during the second year. No satisfactory ex-planation was 

 apparent for blood collector G's increase of 0.31 per cent of jellied samples during 

 the second season. 



