SHANK COLORS IN DOMESTIC FOWL. 24I 



consequently it is not made up of strata corresponding to the 

 rate and corneal layers of the outer skin. The upper portion 

 consists of fine bundles of connective tissue and elastic fibres 

 closely interlaced and running in all directions. Below lies a 

 much looser fabric of larger and more or less horizontal bundles 

 in which fibres predominate. Stained sections show numerous 

 round or oval cells in the upper portions. Below the dermis 

 proper is the subcutaneous connective tissue interspersed with 

 the masses of the panniculus adiposus. The lower and middle 

 corium is richly supplied with blood vessels which give off 

 capillaries. These capillaries penetrate the portions bordering 

 the epidermis, which they appear to touch without penetrating. 

 Nerves also, according to Hanau, are numerous, the fine 

 branches of which in like manner run to the epidermal border 

 without extending beyond. Fatty masses, in varying quantities, 

 are frequently to be found scattered through all parts of the 

 dermis. 



Pigmentation. 



The various colors seen in the shank are due to the presence 

 of pigment of two kinds : orange-yellow, and brownish-black. 

 (3), (4), (2)._ 



Yellow. — This is a lipochrome pigment, which, when present, 

 is diffused through all parts of the cell; when dilute, it gives a 

 yellow hue; when concentrated, orange. It is found in the 

 epidermis and in the fatty masses of and beneath the corium. 

 and is probabl}' identical with the yellow fat color found in 

 other portions of the body. Various names have been given it. 

 Gadow (2) sa3'S, concerning feather color: "Ontochrin, Kithne, 

 der gelbe Dotterfarbstofif aus den Hiihnereiern, ist wahrschein- 

 lich identisch mit dem gelben Farbstoffe der Fussbekleidung 

 der \"ogel. . . . Krukenberg nennt diesen Stoff Coriosul- 

 furin und halt ihn wie Zoonerythrin und Zooxanthin fiir ein 

 gefarbetes fettes Oel. Moglicherweise ist es dasselbe wie 

 Zooxanthin." 



Black-brown. — The dark color is carried in microscopic pig- 

 ment granules, which may be scattered through the ordinary cells 

 or be confined to special pigment cells. The former are con- 

 fined to the epidermis, while the latter may occur in both layers, 

 but infrequently in the epidermis. When granules are present 



