4 CIRCULAR 3 9 2, U. S. DEPARTMENT OF AGRICULTURE 



Figure 2. — American foulbrood : A, Healthy brood in new brood comb : B, old brood comb 

 with an advanced case of American foulbrood ; C, scales of larvae dead of American 

 foulbrood on a cross section of a new comb ; D, scales of larvae dead of American foul- 

 brood in an old brood comb. 



