POULTRY DISEASES AND THEIR TREATMENT 
Cause. This disease is often clearly a 
later stage of roup. It is difficult to say 
where one ends and the other begins. It 
has been claimed that the organism is the 
same as that which causes diphtheria in 
Fic. 11.—DIPHTHERITIC ROUP 
b, lower beak; #, tongue; m, false membrane. 
(After Harrison and Streit.) 
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