A kind of domestic fowl, called in western countries “silky fowl” or “negro fowl,” has its origin in the Orient. Their most striking characteristics are, first, the extra toes on the inner side of the foot, showing a complete or incomplete adherence of first and second of them, and second, marked pigmentation of every part of the body. Although the feathers of genuine negro fowls are pure white or pure black, the skin itself always appears extremely bluish brown in color and contains a number of chromatophores in the cutaneous and subcutaneous connective tissue. The periosteum and endosteum, dura and pia mater, perivascular connective tissue and serosa also show the brown coloration, diffuse and spotted. Of the organs the testicles and ovaries are most strongly tinted; the lungs show spotted pigmentation as in anthracosis. The parenchymatous organs, namely, the liver, kidney, and spleen, are usually free from abnormal pigmentation. The coloration of bone is so remarkable that we suspected at first its identity with animal ochronosis. Microscopically we ascertain that the brown coloration everywhere in the body is due to the existence of a large number of chromatophores in the interstitial tissue, especially along the course of the blood-vessels. The chromatophores assume a form quite similar to those in normal fowl, having a number of irregular long and slender processes and fine yellowish brown pigment granules with an entire similarity to melanin in microscopical appearance. Pigment granules in the cells which are in resting stage are very fine and equal in size. When stimulated by experimental means they become irregular in size, and the cells lose their processes, taking a round shape like any other plastic cells.
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Oct 12, 1963
Bert N La Du + 1
Open Access