596 



DISEASES OF THE SKIN. 



several authors have described an acarus similar to the sarcoptes^ 

 which is found upon the surface of the skin and in the connective 

 tissue. It sometimes occasions a cutaneous eruption which is 

 similar to mange (Unterberger). 



Other Cutaneous Diseases of Poultry Caused by Animal 



Parasites. 



Among other parasites of birds which determine particular dis- 

 eases we must mention the following : 



1. Harpirhynchus of the domestic pigeon. The Harpi- 

 rhynchus nidulans has its habitat in the balbs of the feathers, which 

 are swollen into capsules or yellow cysts of the size of a pea to that 

 of an acorn. They are also found in cutaneous tumors of the sternal 

 region and of the lower part of the wings. 



The contents of these cysts consist almost exclusively of harpi- 

 rhynchi ; there are found in them by hundreds. When these 

 lesions exist in large number on the surface of the skin the animals 

 lose flesh and die. 



2. Yermiform Hypodectes of the pigeon {Hypodectes 

 columharum). They are located in the subcutaneous cellular tissue, 

 on the surface of the peritoneum, and in the connective tissue of 

 the aorta. This parasite is found to represent the hypopial nympha 

 of an acarina which was before unknown. It occasions slight 

 phlegmasia and moulting trouble, and prevents regeneration of the 

 feathers. 



3. Syringophiles of the chicken and pigeon (Syringo- 

 philus \^Picobia] bipectinatus). They live in the tail quills and 

 wing feathers, producing the deformation and later the falling out 

 of these organs as well as irregularities of the moulting process. 

 The stem of the feathers has lost its transparency ; it is generally 

 bent at its extremity, and its puip is replaced by an opaque, puru- 

 lent matter. These are the only symptoms to which they give rise. 



According to Heller, in Schleswig-Holstein 70 to 90 per cent, 

 of the chickens are said to carry Syringophilus bipectinatus. In 

 the peacock we find a distinct species, Syringophilus [Cheyletus'] 

 uncinatus. 



4. Acarina of pigeon feathers (Ziiru). This species is 

 sometimes found in considerable quantity between the feathers; 

 it may occasion emaciation and a fatal exhaustion. According to 

 Zurn, thrush of the anterior regions of the head in the pigeon is 



