In this paper, changes in the concentration of inosine monophosphate (IMP) of muscles in Taihe Silkies chickens from 2 to 28 weeks of age were studied. The results showed that: (1) with increasing age, IMP content of muscles decreased continuously. (2) the relationship between body weight and IMP content of musculus pectoralis major was significantly negative (p<0.01), so was body weight and IMP content of musculus peronaeus, and their coefficients of correlation were -0.45, -0.38 respectively; the relationship between IMP contents of musculus pectoralis major and that of musculus peronaeus was more significantly positive (p<0.01), and its coefficient of correlation was 0.59. (3) by multiple regression analysis, changes of IMP content of muscles depended on the weeks of age and body weight. (4) from 2 to 28 weeks of age, the heritabilities of IMP content of musculus pectoralis major were calculated between 0.33-0.48, and those of musculus peronaeus were calculated between 0.51-0.69.

Chick embryos from stage 14 to stage 31 were studied by means of serial section and light microscopy in order to learn the relationship between the settlement sites of the primordial germ cells (PGCs) and the forming genital ridge. The results showed that: when embryo hatched for 53-56 h, the PGCs reached the coelomic epithelial tissue where gonad would be formed, meanwhile the epithelial tissue began thicker before the PGCs reached. Before stage 19, the final region the PGCs arrived was the thickened portion of the coelomic epithelium, the glycogen in the PGCs cytoplasm maintenance remained unchanged. However at the 3.5-5th hatching day, the glycogen in the PGCs cytoplasm reduced gradually. On the 6th hatching day, the gonad of the embryo appeared the feature of ovary, and the glycogen in the PGCs cytoplasm reduced further. On the 7th hatching day, the differentiation of ovary or testis was obvious and the glycogen in the PGCs cytoplasm later disappeared.