Histological, Histochemical and Electron Microscopic Studies on the Development of the Liver of the Domestic Fowl

Using the white leghorn, from 3 day-old chick embryo to 2.5 years cock, the liver tissue was examined histologically, histochemically and electron-microscopically. At 3 days of incubation the liver cell-cords formation begins. At 6-7 days of incubation, the liver cells are arranged in two rows on the longitudinal section of the liver cell-cords and radially on the transverse section. The bile canaliculi are found also at 3 days of incubation, and are surrounded by about 10 liver cells at 4 days on the transverse section. The number of the cells forming the bile canaliculi is decreased with the days, and in adult domestic fowl it becomes about 4 or 5. On the 9 days of incubation, the formation of the GLISSON's capsule with interlobular- and central-vein is noticed, and the inter-lobular artery and inter-lobular bile duct are seen at 11 days. The whole liver organization is completed histologically at 15 days of incubation, but even in the adult animal the lobular formation of the liver is not so complete as seen in that of the mammals. At 3 days of incubation, it is found the infiltration of the blood capillary into the liver tissue, in which the blood formation cells are noticed. Sometimes the figure, which is considered that the blood cells are transformed from the endothelial region, are found. These blood cell formation in the blood capillary of the liver tissue is seen often in 10 day-old chick embryo, and it becomes rare from 20 days of incubation. The lymphocytes appear in the connective tissue of GLISSON's capsule at 10 days of incubation, and in the liver parenchyme at 10 day-old chick. From 30 days after hatching, the author can find lymph node. In the domestic fowl the lymph node is always seen in the connective tissue and liver parenchyme. The small number of eosinophilic leucocytes were seen in the connective tissue at 11 days of incubation and in the liver parenchyme of 5 days chick, but their number is not increased with days. The glycogen appears at 6 days of incubation and it is increased remarkably with embryonic days. After hatching it is decreased rapidly till 2 days, and then this substance is increased again. The alkaline-phosphatase reaction is always strongly positive in the endothelium of the inter-lobular artery and vein and of the sinusoid, while the acid-phosphatase reaction is positive in the liver cells. From the end of the embryonic day, the KUPFFER's cells become clearly positive in acid-phosphatase reaction, which suggests t