Symptoms. 431 



but which later assume a more grayish-yellow color, and are 

 composed of horny or fatty degenerated epithelial cells. By 

 gradual enlargement these develop to pea-sized, yellow or dark- 

 brown nodes whose surfaces are warty, dry and firm, the in- 

 terior contents being composed of a yellow, fatty paste (Fig. 65) . 

 Sometimes they are so abundant that they touch and even 

 coalesce with the result that the highly reddened and easily 

 bleeding skin forms thick cohesive scabs. The comb and wattles 

 are in consequence much thickened and deformed. The margins 

 of the nasal orifices and still more those of the eyelids also 

 become thickened so that eventually the eyes are completely 

 closed. Should the inflammatory process spread to the con- 

 junctival tissue much caseous and purulent secretion accumu- 

 lates in the conjunctival sac which gradually effects a pressure 

 atrophy of the eyes, or a corneal inflammation develops, which 

 may become complicated with a purulent panophthalmitis. 



Nodules and nodes similar to those on the head develop 

 in some cases on other portions of the body, especially in the 

 vicinity of the cloaca, on the under surface of the wings, on 

 the neck, on the rump, particularly on unfeathered areas. Here 

 they sometimes attain the size of a hazelnut and may even de- 

 velop into horny or callous growths. Such large growths which 

 have an irregular surface, may, by the exercise of considerable 

 force, be removed or broken off from the skin, which will expose 

 the interior cavity filled with a thick cheesy mass, while vertical 

 sections show wavy layers running more or less parallel with 

 the skin surface. 



As long as the disease is confined to the skin the general 

 condition usually remains undisturbed; only when it is widely 

 distributed over the surface of the skin marked emaciation 

 is likely to occur. 



In warmer countries a virulent diffuse form of the disease occurs 

 whereby the skin shows no tumor formation but a flat papular thicken- 

 ing and the affected areas become in a few days covered with dry crusts. 

 Febrile symptoms may also occur, not followed by nodules but by 

 reddish-violet pustules, which turn later white and finally yellow, and 

 which eventually dry up and form brownish crusts, or death follows 

 after 4 to 5 days of the disease (Reischauer) . A malignant course 

 was also observed by Klee on a chicken farm where a diffuse inflamma- 

 tion developed over the body associated with seborrhoea and warty 

 growths. All hens so diseased died within 4 to 5 days. 



The second form which has hitherto been considered ex- 

 clusively as avian diphtheria, begins, also without any niarked 

 disturbance of the general condition, with a local affection of 

 one of the mucous membranes of the head, usually the mouth. 

 In some cases there develop on the otherwise smooth surface 

 which is at times only slightly reddened, small spherical or 

 oval yellowish-white spots, which gradually spread and finally 

 form extensive membranes. In other cases the mucous mem- 

 brane assumes a dark red color, soon followed by a gray deposit 



