C. B.TICEHURST: WOOD-PIGEON DIPHTHERIA. 77 



fauces, and base of tongue, and the glands in the neigh- 

 bourhood enlarged. The mass is sometimes so large as 

 to block entirely the gullet, though it is much rarer to 

 find the windpipe pressed on to any extent ; the parts 

 around the " membrane " are inflamed. With the 

 formation of this false membrane death of the underlying 

 tissues takes place, even the bones being affected ; thus 

 in advanced cases it was common to find the base of the 

 skull reduced to a cheesy mass. In a few cases the 

 membrane extended down the gullet into the crop, and 

 in one instance it had perforated the proventriculus, and 

 the bird had died from peritonitis which had resulted. 



In most cases the crop was empty. The condition of 

 the birds varied, some being very wasted, others being 

 in good condition. Those which had contracted a virulent 

 type of the disease, or had a low resisting power, succumbed 

 quickly, and so had not time to waste, while those which 

 had lingered long with the disease, or had the gullet 

 occluded, partially or wholly, were correspondingly thin. 



