15 



mucous masses in the eye and in the glanular canals. A certain interchange, 

 therefore, seemed to exist between the two. The transformed nuclei were 

 fairly resistent, which might be due to the condition of the nuclear membranes, 

 for, while the cells themselves decayed, the nuclei lasted for a long time. They 

 were constantly found in all more severe cases of pseudo-membranes. Trans- 

 formed nuclei mig'ht be seen in the slimy-putrid secretions of mucous mem- 

 branes, in the cheese-like exudations in the nostrils, eyes, bronchial tubes, lungs, 

 pleural and peritoneal folds ; or. in other words, wherever there were epithelial 

 or endothelial cells. They were not found in the solid masses o'i matter in 

 the lids and in other submucous or subcutaneous tissue. 



In the above-mentioned jelly-like exudations, the products in the eyes of 

 fowls 35, 36, etc.. the epithelial nuclei were greatly swollen. They were homo- 

 geneous, clear, with or without nucleoli. 



While the changes described in the middle epithelial layer were taking 

 place, compact masses of pus were deposited over this layer and the pseudo- 

 membranes were thus formed. All membranes which could be easily re- 

 moved became separated from the region of the middle epithelial layer (Fig. 

 i). We then had typical croup membranes and a regeneration of the epithelium 

 took place from the lower layers. In those cases in which the membranes 

 were firmly attached, even the lowest epithelial layers were very much altered. 

 They were swollen and loosened by fibrous purulent exudations. Under the 

 lasting invasions of the leucocytes, the constituents of the epithelium were 

 lost. The compact mass of epithelial pseudo-membrane advanced towards the 

 lower layer of the epithelium, and finally reached the submucous tissue and thus 

 became a typical diphtheritic membrane. 



Submucous glands were often partly, or altogether filled with leucocytes. 

 In typical diphtheritic membranes small quantities of fibrous exudation were 

 found especially in the region of groups of bacteria. The croup-membranes, 

 the cheese-like bodies in nostrils and eye-lids, in bronchii. pleura and periton- 

 eum, as well as the firm masses in the different tumors of the head, were made 

 up of leucocytes, granular detritus, of bacteria and eventually, of a remnant 

 of epithelium and foreign bodies. 



Bodies Resembling Protozoa. 



When the secretions and exudations of birds affected wiih roup contained 

 remains of epithelium, the round, protozoa-like epithelial nuclei, referred to 

 above, were present. Besides these, other very different bodies, which often 

 more or less resembled the protozoa described as the cause of fowl diphtheria, 

 or epithelioma contagiosum, were seen. No case of epithelioma contagiosum 

 came under our observation. Table i shows some of the protozoa-like bodies 

 found. These figures were drawn from fresh preparations which had been 

 stained either with methylene blue, gentian violet, fuchsin, or Lugol's solution. 

 The material was quite fresh, or had been stained without drying or heating. 

 Many peculiarities could be distinguished with the methylene blue or Lugol's 

 solution. The commonest forms of protozoa-like bodies were the swollen 

 epithelial nuclei, which have been more minutely described above. They were 



