8 MASS. EXPERIMENT STATION BULLETIN 163. 



in tube No. 2, 0.15 cubic centimeters serum (final dilution 1-200), and in 

 tube No. 3, 0.3 cubic centimeters diluted serum. In some cases a third 

 tube of test fluid has been used with a 1-500 dilution of serum. All tubes 

 have been labelled with hen numbers, dilution of serum contained, and 

 shaken to afford thorough mixing of the test fluid and serum. In each set 

 of tests one tube containing test fluid alone has been placed as a second 

 means of controlling the results. At this point the tubes have been set 

 in the incubator at 38° C, and readings have been made at the end of 

 twenty-four, forty-eight and seventy-two hours. 



In tests made on infected flocks readings of the tubes showed that in 

 some containing test fluid and serum, fine, flakelike masses had settled 

 to the bottom and sides, leaving the supernatant fluid clear. In other 

 tubes the mixture of test fluid and serum remained hazy as it was at the 

 time tests were set up, and no flaky sediment appeared. In the first case 

 it is evident that the serum contained an agglutinin which had caused 

 the agglutination of the bacteria of the test fluid, and all birds with sera 

 reacting in such a way have been reported as positive reactors. 



For all flocks tested record cards of all details have been filed, the mate- 

 rial including, in addition to records of hen numbers and all readings of 

 tubes, such data as date of drawing of blood samples, date same have been 

 received in laboratory, their condition, and notes on the test fluid. From 

 these records, at the conclusion of the tests, a complete report can be sent 

 to the owner of the flock. In these reports a list of the numbers of all 

 hens tested has been sent, the numbers of positive reactors being preceded 

 by a red star. Together with tliis list has been sent a recommendation 

 to be followed in the eradication of infection from the flock. In addition 

 to the above data the laboratory record cards include data received from 

 the owner concerning the results he has attained from tested stock. 



Data secured prom Agglutination Tests. 



In organizing for publication the data gained up to the present time 

 from our work with the agglutination test it has seemed wise to divide a 

 map of the State of Massachusetts into districts, and, using these districts 

 as units, to make a chart showing the results of the agglutination tests on 

 representative flocks in these areas. 



This chart gives the number of the district from which the flock has 

 been chosen, — this number corresponding to number of district on map, 

 — the laboratory number of each bird, owner's number of bird, results of 

 the tests in dilutions 1-100 and 1-200 ( — indicates a negative, 4- a posi- 

 tive reaction), total numbers of individuals tested in flock, number reacting 

 positively, and percentage of positive reactors. In this way it will be possi- 

 ble for poultrymen in the various districts to get complete data from 

 representative flocks. 



