ERADICATION OF PULLORUM DISEASE 1931-32 11 



The following observations were associated with frequent collections of 

 blood samples from 19 birds (10 pullets and 9 cockerels). The birds were housed 

 in a warm room and during the day were placed in a yard when the weather 

 permitted. 



1. Jellying appeared in from to 70 per cent of the samples which were 

 exposed to 2° C. immediately after collection and held at this temperature for 

 from 3 to 40 hours. 



2. Jellying appeared less frequently when the samples were subjected to a 

 temperature of 10° C. for similar periods of time. 



3. Jellying did not appear in the samples which were held at 22° C. for 

 two hours after collection and then placed at 2 ° C. for varying periods of time. 



4. The temperature of the tubes at the time of collection appeared to have 

 no influence upon jellying. Quadruplicate samples were collected. Two warm 

 tubes (approximately 22° C.) and two co'.d tubes (approximately 2° C.) were 

 used. One warm-tube sample was held at 22° C. and the other at 2° C. The cold- 

 tube samples were handled in the same way. 



5. Jellying was slightly less frequent when samples were collected in 11 x 

 100 mm. tubes then when 8 x 77 mm. tubes were used. 



6. Jellying appeared when blood samples were centrifuged immediately 

 after collection. 



7. Attempts to produce jellied samples by collecting blood into tubes which 

 had been washed in dilute hydrochloric acid were unsuccessful. The same 

 observation was made when the tubes were washed in sodium hydroxide and in- 

 completely rinsed before use. 



8. Blood samples were taken in duplicate while the birds were in the warm 

 room. Half of the samples were placed at a temperature of 0° C. for 1 hour and 

 the other half held at the room temperature. Then all samples were placed in a 

 refrigerator (8° C.) for approximately 24 hours. Jellying occurred among the 

 samples exposed to the lower temperature and did not occur among those exposed 

 to the room temperature. 



9. On different occasions, blood samples were taken in duplicate while the 

 birds were in the yard, and when the atmospheric temperatures varied from 

 1 ° to 12 ° C. Half of the samples were placed in the operator's vest pockets and 

 half exposed to the atmospheric temperature during the course of blood collec- 

 tion (approximately 30 minutes). Then the former were held at room tempera- 

 ture, and the latter at the prevailing atmospheric temperature for 1 hour. Final- 

 ly all samples were placed in a refrigerator (8° C.) for approximately 24 hours. 

 Jellying occurred among the samples exposed to the atmospheric temperatures 

 and did not occur among the samples placed in the operator's vest pockets. 



These preliminary observations were made upon a small number of birds 

 maintained at the laboratory. It appeared that certain of these earlier general 

 and preliminary observations should be investigated further. Arrangements 

 were made to do this, both in the field and in the laboratory. 



Experimental Procedure and Results 



I. Instructions were given to two blood collectors to place the even num- 

 bered samples into their inner pockets for about 30 minutes, and then place them 

 in the containers with the odd numbered samples which were to be handled in 

 the routine manner. Data concerning the observations are presented as follows: 



Blood Number Even Samples Odd Samples 



Collector of Samples Jellied Per Cent Jellied Per Cent 



A 4,011 88 4.4 290 14.4 



B 3,009 62 4.1 207 13.7 



