82 



TECHNICAL BULLETIN 5. 



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

 laid by Positiiely Reacting Hens.''- 



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

 Journal of Immunology, Vol. 2, p. 463, 1917, as follows: C=complete agglutination; ? = doubtfu] 

 agglutination; = no agglutination. 



These cxioeriments indicate that in chicks hutched 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 i)owcr to their 

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

 Jias not as vet been determined. 



