Abstract
Vitamin K_1 was given to the mice of 1 to 7 day-old in the dose of 0.1 to 0.7 mg and following results were obtained. 1) Though vitamin K_1 of 0.1 to 0.7 mg in total was given to mice, the change in hair colour to yellow did not occur and the body weight increased normally. Even when the dosage was further increased, the hair colour of mice did not turn to yellow. 2) The rough surfaced endoplasmic reticulum kept the normal stratiform arrangement, and distributed evenly over the whole cytoplasm without noticeable changes. 3) The shape of mitochondria was generally round or elliptic, and was not differ from the normal condition. However in the mitochondria of 3 day-old mice given 0.3 mg of vitamin K_1,the metamorphosis was recognized. 5) In the 2 day-old mice, the development of Golgi apparatus was very good. In the other mice no remarkable difference was recognized compared with the control group.
