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TECHNICAL BULLETIN 5. 



Table 6. — Records of Agglutination Tests on Chicks hatched from Eggs 

 laid by Positively Reacting Hens. ^ 



' The symbols indicating various degrees of agglutination have been taken from Hadley, 

 Journal of Immunology, Vol. 2, p. 46.3, 1917, as follows: C=complete agglutination; ?=doubtfuI 

 agglutination; = no agglutination. 



These experiments indicate that in chicks liatched from eggs laid by 

 positively reacting hens, at least six months' time should elapse before 

 the normal agglutination power of such sera would be sufficiently definite 

 to furnish indication of past or present infection. The birds reared from 

 hens 8001, 8139 and 8810 never showed any agglutinative power to their 

 blood sera. The length of time a serum maintains its agglutination power 

 .has not as yet been detennined. 



